Archive of Our Own ^beta

Tanjiro never realized how horrifying Time actually was.

Time causes change. It causes everyone to advance with its passage because nothing could stop it. It caused everyone to forget things, lose power and even Age.

Eventually, there remained nothing.

It's an Ultimate Rule that seemingly cannot be bypassed by any living beings.

But, Tanjiro realizes another horrifying thing related to time. And he has firsthand experience as well.

Getting sent into a Time Period that isn't your own, Centuries before you were ever born. In an Era that you knew nothing about, so separate from what you knew that you could believe this was another world, with absolutely no Friends, Families, or even Allies.

Just yourself.

Isn't that terrifying?

To find yourself in a void of nothing. To find yourself stuck in a place you cannot hope to escape.

For your last sight to be of a Sister horrified and a Demon that cackled with glee at their work?

And then, for the pain to flare as everything shifts. As everything moves. His eyes cannot see, but he is pulled regardless.

Seconds, Minutes, Hours, Days, Years, Decades, Centuries? How long was he pulled?

How long did he suffer through pain as his Mind and Body get torn apart? And then, to simply stand in the middle of nowhere, as if what had happened so long ago, yet so shortly, hadn't taken place at all.

Tanjiro wonders if he didn't simply break, the day he found himself back in Time, a Thousand Years ago in the Heian Era.

His mind certainly believed so, considering how messy his Memories were at the time. How he could barely remember anything but the basics of his Life.

In hindsight, that was the first sign of something else being wrong.

His Brain had been damaged by the Travel through time, but it wasn't the only thing. His whole body was severely weakened. Unable to properly Breathe meant he no longer could use Total Concentration Breathing. That meant his Lungs were also damaged. His Senses felt weaker, duller. That included his Nose.

And, unknowingly, so did his Cells. In such a manner it locked away something he would chase after, Centuries later.

Kamado Tanjiro had gone back through time and ended up with a weak and frail body that left way for Diseases to take root.

By all technicalities, Kamado Tanjiro had perished on the day he was ambushed by the Demon. One Upper Moon Five. One he would not remember for Centuries to come.

What was left behind, was just a boy, hardly an Adult, who didn't realize his situation yet, but would do so soon.

And it makes him wonder if this entire event, this entire ''Birth'' of his, was the reason why he sought out Eternity.

To be a being that cannot be affected by time, no matter the Era. To be a being that Eternally was strong, no matter the time.

Was this why he sought it out? Or... did it start elsewhere?

Did it start when he realized his body had become weaker, as a consequence of Time-Traveling, and would only continue to grow weaker as time passed?

Did it start when he realized that finding employment in a completely different Era was much harder than he'd ever imagined, so much so that he wished Money wasn't needed?

Or perhaps... perhaps, he should attribute it to something else. Another Event in his Life that changes it all.

So unexpected, yet entirely related to the two above matters.

His Illness.

Illnesses, as Tanjiro realizes, are something uncaring.

It grabs onto anyone. No matter how strong you are. No matter how healthy you may be believed to be. It hits everyone mercilessly the moment you weaken.

Just like with his Father, Tanjuro.

He who was a strong man, still perished because his Body grew weak. No matter the power he held. No matter the presence he gave...

He was only Human, after all.

And a Human, no matter how you saw it, has limits. They cannot do everything they set out to do with their Weak Flesh and Frail Minds.

Is it a wonder then, that he despises seeing Ill people, but even more, that he pities them all the more because a Cure may never come their way?

Well...

He never did imagine he would be in a similar situation to his Father, but all the worse because his Body was in even worse health than Tanjuro's ever was.

Tanjiro looks back on it, and laughs.

The Illness has an unknown point of Origin.

When Tanjiro does realize he is Ill, it's within a Year in the past. Something he has been able to confirm by just asking around for the Era.

It's nothing serious at first. He just had a harder time breathing and felt overall weaker, but he was able to shrug it off over time.

He assumed he'd just contracted an Illness that would fade in a few days. That was the general rule with minor Illnesses.

And he'd know if it was Major. He'd seen how badly his Father's own Illness had gotten. He briefly was worried about it, but cast it aside in his own mind.

Instead, he kept focusing on work.

He has no other priorities besides survival at this time. Because right now, he truly has no other options since they're impossible to attain.

And to his luck, he does end up being employed as a Servant to the Ubuyashiki Clan during that initial first-year span. Though they weren't called Ubuyashiki, but Kibutsuji's back then.

Hence, he doesn't give a single sign of recognition upon working for the Clan. They're a rich family that's willing to pay, and Tanjiro is willing to work hard.

It's a win-win for both of them.

But after a year of hard work, earning something for his living, he ends up noticing that his Illness grew to degrade.

Initially, they had assumed it was because he was working too hard. So they had decided to give him a break since he'd deserved it with all his hard work. But then, when the degradation didn't subdue and in fact only grew worse, they all agreed to call for a Doctor.

Except, the Origin point of the Illness remained unknown. It was not something of this Era, and Tanjiro truthfully doubted it was even something of his own time.

Perhaps it was the Price to pay for breaking the Laws of Time. Perhaps a Curse cast by the Gods themselves for breaking a Supreme Law, even by accident.

Or perhaps not.

The Doctor serving the Kibutsuji's couldn't identify the Illness. And the next one they employed couldn't either.

Tanjiro tried to continue on, but it became clear this Illness was gradually killing him.

His Body simply began to fail him.

Within a year, he had a hard time moving, then within a second, he actually began coughing out Blood.

Within the Third, he couldn't even move anymore, much less stand upright.

From 16 to 19, he went from Physically capable to a cripple. And the Doctor called afterward was certain he would die at 20.

One Year left, bedridden, and with no Cure.

Tanjiro wasn't sure how to feel about this anymore.

Outraged? Acceptant?

He just didn't know what to feel. Perhaps he already accepted his fate on what was basically his Deathbed, and yet... he wondered if there couldn't be a way out of this.

Because he was dying without ever seeing anyone he cared about.

He never would see any of them. Not Nezuko. Not Kanao. Not Zenitsu. Not Inosuke. Not Aoi. Not Giyuu. Not Shinobu. Not anyone.

This was it for him.

Perhaps desiring to see his Friends and Family again was a futile thing, considering he knew he was in an Era that was not his own. In an Era so far back, not even his parents were born. Yet, he couldn't help it.

From his fractured Memories, he remembered them all the clearest. They were truthfully the last things he remembered with Clarity.

They were everything he had left, besides the vague outline of his life he has in his mind. They were the last traces of the life back in his time that he could truly cherish without wondering if he was missing something.

And he felt horrible for it.

Everything else? Some of them were clearer than the blurrier ones.

Perhaps God had listened to him. Perhaps pure chance came his way. Perhaps destiny truly was at play. Or perhaps it was just sheer coincidence...

But as his 19th Birthday passed? A Generous Doctor heard of his Illness and was willing to try an experimental Medicine on him.

From what he was able to hear, because the cure was in its experimental stages, it was a long process. It may work, or it may not. Either way, all the previous Doctors could do was extend his Life.

This one? He may be able to actually Cure him through this Process. If he survived up to that point. And while Tanjiro of course has some skepticism, he doesn't deny it.

Better give that Medicine a chance, if nothing else.

Kamado Tanjiro takes the Medicine. And for it, everything changes.

Thinking about it again, Tanjiro wondered how this Doctor discovered the Blue Spider Lily to begin with.

Did he just stumble upon it? Was he sold it? Did someone tell him they saw the Flower bloom, and he just so happened to be there when it did?

Clearly, it couldn't have been cultivated by his own hands, or Tanjiro knows he would have found it when he went to Tokyo, decades later.

The Doctor had a successor, after all. And that Successor had one of his own. And on and on until he found them.

It practically was one of the first places he went to after he'd gotten his priorities straight.

How did this random man find such a Powerful yet complicated Flower? And how come there weren't more of them?

Tanjiro may never know. But he could wonder.

A Pair of Blood-Red Eyes watched, opening and closing themselves several times. A reflection of himself is what he watched from the edge of a Lake.

Slitted pupils trailed off and moved up to his forehead. More to the left side where a Scar remained.

The Mark it had was gone since the Time-Travel, yet, this wound... it should be gone, no?

If he had learned anything in the past week since his Carnage at the Kibutsuji Estate, it was that his Regeneration was strong. In fact, he would dare say it made him Immortal. Almost.

The many other Scars he undoubtedly obtained during his time as a Demon Slayer were all gone. Healed by his newfound Power. Yet this thing remained.

Why?

Why did it not heal? Why did it not fade like every other wound he sustained?

Tanjiro knows he should be more bothered by this. And he is bothered, but it's such a small and insignificant thing, how little of a bother he actually sees it as.

Tanjiro realizes that this is wrong on so many levels that he should be panicking. Even after a Week. He should not be feeling so... calm. So uninterested, almost.

Yet he is.

He doesn't see it as an issue emotionally. He feels barely anything on an emotional level. Mentally, he still realizes it. But, when your Emotions and Intelligence are detached while your Instincts are prominent things, it causes issues.

It doesn't help Tanjiro isn't sure as to why he's so emotionally detached, apathetic even, to all this. How it even started.

But, he can guess it's because of him becoming a Demon.

Nezuko had a similar, but still widely different case, did she not?

She'd reverted into the state of a Child at first. Clearly weary of him for some reason, but Urokodaki had helped her develop Mentally again during his time training to be a Slayer. Remove those inhibitions one by one.

By the time he went to the Final Selection, she was mostly back to herself.

But even when she spoke, he had not been able to figure out why.

Until... until that populated City.

It actually stirs something in him, Tanjiro realizes. As he watches his reflection on a Lake, he actually feels a small amount of disbelief. Realization about the matter.

He'd met the Demon Progenitor. Kamado Tanjiro.

And it suddenly explained why Nezuko had been so weary of him, so distrustful until the... District. Against those Upper Moons. Six, right?

She saw him as the Murderer, didn't she?

And... it stirs something again. Sorrow.

Maybe he isn't as emotionally detached as he believed.

After all, he also realizes the implication.

Tanjiro and Tanjiro looked alike, no? They could pass off as Twin's even. Demon and Human sharing the same name, and nearly exact same appearance.

Save for their forehead.

He wonders if someone would have laughed if the realization had hit them. Because there is no other answer.

''He and I are one and the same.''

He says this aloud. A fact said to the World itself a Thousand years ago. But his tone remains even.

There is no outward shock, outrage, despair, disbelief or anything like that. And even internally, it's severally muted to simple surprise.

A simple ''Oh'' and that's it.

...he really should be more horrified by both of those things. Or even what he had to do now that he was a Demon.

It's a universal Rule, no matter what type of Demon you were.

Tanjiro kept staring at his own reflection when thinking about it, unchanging in the calm, if not cold night.

He opened his mouth briefly, and it showed his fangs.

He would kill. He would eat people again, bite into their skin with his Teeth. And doing so without a shred of hesitation.

Even if the Human was his Doctor. Or the Ubayashikis still called Kibutsujis he'd run away from after causing a Massacre through his Starvation.

Tanjiro knows he should be horrified because that's how he would react. He knows that Nezuko would not approve. That no one would.

But here's the thing.

Tanjiro isn't Nezuko.

Be it he lacks something, that he lost something, or that Nezuko truly just had more willpower than he'd ever imagined, he cannot go without eating Humans. It's impossible.

His very Instinct, the dominant part of him, demanded he be satiated so he would not be weak. So he would be Supreme.

And here is the thing. Tanjiro doesn't truly fight back against it. After all, when your Emotions are muted and your Instincts are more dominant, why fight them?

Besides his lack of emotions and its consequences, he comes to a realization.

With this body... he can fight against the effects of Time itself. Ageless, if his Future self was anything to go by, and Powerful enough he truthfully shouldn't need to worry about Power ever again. And he would only grow more powerful the more he ate, supposedly.

Though... he wouldn't mind using Water or Sun Breathing again. If only he could use Total Concentration Breathing again like he used to...

Yet, even though his body was supposedly in Peak Condition, it's like his Body Instinctually knows he is still a man who became Ill. He's barely able to use Total Concentration Breathing.

He does not tire, yet he cannot strain his Lungs at the risk of going through a coughing fit.

It's a paradoxical situation, isn't it?

He would need to try out this whole thing further, discover where his limits truly lay, but that was a matter for later.

For now, Tanjiro had only one true goal in mind.

Satiate himself.

There is a period of time when many people would swear they saw a man with Blood-Red eyes come after them. Success or Failure, all saw those eyes devour.

This was the first sign of a Demon, and from it, slowly, Demon Slayers would begin to rise.

But that was slow.

And so, for a time, the Demon King thrived.

In his hunt for food, Tanjiro stumbled upon turning people into Demons.

Literally for that matter. Tanjiro remembers the Lesson he was taught. That the Demon King's Blood was the only thing capable of turning other people into Demons. Supposedly at least.

Tamayo had shown she had discovered a way to do exactly that, but the process was lengthy, and chances of failures were much more likely to happen.

It was by pure chance someone cut him and his Blood flew out into a dying Man's mouth. He'd attacked a Group, and he'd wondered if having someone by his side would be a good idea or not.

The Road he Traveled was quite lonely, after all.

And so, the first Demon was born. And thereafter, promptly killed.

Tanjiro doesn't think much of it, wondering why his... other self -if that's even the correct term to use- would have even made more Demons if he was this powerful. It couldn't have been due to loneliness, could it?

He would learn why, in due time. And indeed, it was not because of loneliness.

But for now, he dealt with life as a Demon that had severely muted emotions. And eventually, Tanjiro thought: ''Why not feel again?''

His control over his own Biology was something to behold, considering what he could do. Making sure he could feel again... it wouldn't be too hard.

After all, his own Cells were what stopped him from feeling. So it was logical that he could undo what his own Body did.

And it wasn't hard.

He just needed to reverse what had started it. Simply find it, then undo it, and so, he felt again.

There was however one issue that came afterward, when he did feel again.

First, he felt joy. For the first time in a Century, he felt it. Because he had succeeded in feeling again.

But then?

Guilt

He was practically showered in it after less than a minute.

Guiltguilguiltguiltguilt!

His conscience was fully returned, and with it, that emotion he should have felt from the start. That should have stopped him from ever committing any of his actions as a Demon.

Tanjiro cried for the first time in a Century after that.

He failed everyone, didn't he? Even worse than Nezuko. Worse than anyone else.

That Demon at the Temple? Or that Hand Demon? Or those two Demons that had tracked him down. Or that Swamp Demon. Or Lower Five and One? Or even Upper Six? Or any of the other Demons he killed?

He... he killed so many already! Many to satiate himself, but others because they were just in his way. Innocent or Guilty. His Morals rarely stopped him from taking lives.

He was no better than the Demons he'd fought himself!

But... maybe he can change that? Maybe he can do better. Change it all so that his Present simply never happens.

If only to try and repair the damage he had done.

(He thought like that, once)

And so, when he one day finds an Ill man... how can he not help him, by gifting him his Blood?

Everything goes for the better.

Everything goes for the worse.

Eventually, Tanjiro discovers the existence of the Blue Spider Lily after realizing he actually hates being limited to an only Nighttime schedule, and hunts for it. Not remembering that once, his own Mother had shown him that very same Flower he now oh so desired.

After all, gradually, Tanjiro grew to want Eternity. He wanted to be unaffected by time. He wanted to be able to move, talk and breathe as if every day, was simply another day. Because then, could he not take full enjoyment of life?

So how could he possibly accept his weakness to the Sun like that? When it limits him to Night?

When he desires the Sun itself! To feel its touch, to be able to wield its Fire like he once did through a Breath?

He was certain now.

His desire for this Eternity started here and now. Into a being whose emotions were stripped from him initially, is now copping the best way he can.

Help, as he always did since his Youth, and fulfill his idea of Eternity.

This was when the monster came to be. This was when the Demon King rose, and would never stop trying to conquer the Sun.

But of course, at that time, the Demon King wasn't at his lowest point yet. No, that comes later.

The Demon Slayer Corp doesn't rise at the same time as Tanjiro becomes the Demon King. In fact, for nearly Two Centuries, there is nothing fighting against Demons.

Humans are just prey to be slaughtered. A necessary sustenance for a Demon's continued existence. You're just unlucky if you cross a Demon.

Just like a Natural Disaster.

But eventually, someone does have enough.

Funnily enough, it's not the Ubuyashiki's. Because there isn't a Curse that pushes them to be Eternal enemies.

Not yet at least.

Simply a random man. One who tried to fight Demons because he survived. And then gathered up more survivors.

To be truthful, Tanjiro feels impressed when learning of this.

But, he makes a mistake here.

He doesn't take this Demon Slayer Corp seriously. Because it's in its infancy, he doesn't even see them as a threat.

They don't have Breathing Techniques. They don't have any Weapons made out of Nichirin. They don't have much support either.

They're new at this. And while a mistake, a part of Tanjiro did spare them because he was once a part of them.

After all, his Emotions had returned to him a century ago.

But, time does pass. And eventually, the Demon Slayers do become an issue. A century later, an Ubuyashiki is the Leader. One that had enough of a kind heart and power that he decided to help and support the Demon Hunters.

It was around that time that the Breathing Techniques slowly came to be. Of course, without Yoriichi, no one would be able to make it work to its fullest extent. At beast, they boosted their physical strength through a still new Concentration Breathing.

But the idea was there. And slowly, it was being executed.

And so, with additional help, the Demon Slayer Corp actually becomes an issue. But here is the thing.

Their assets are not as well hidden. Wisteria has only recently been discovered to work effectively well, but their widespread use didn't exist. Nichirin Blades meanwhile is only now being discovered.

And so, it doesn't take too long for Tanjiro to discover the location of the Ubuyashiki Head. And only one.

By that point in time, that individual wasn't married.

That should have been a Fatal Mistake.

For Tanjiro moved to kill. But not the usual way. He did something else entirely, for he wanted the Family he once served as a servant, to die another way. Similar to how he himself nearly died. And that?

That was one of his greatest mistakes.

When he walked away, he was unaware the Ubuyashiki had survived. He hadn't died and had instead clung to life. In fact, he clung to life for years to come.

And so, unknowingly, the Curse came to be.

Kokushibou remembers vividly, how it all started. How he ended up meeting that man. How it led him to the Path he now walked.

He was an Adult by then, but he hadn't become a Demon Slayer yet. He was simply a Man that was married and had children.

So he wouldn't have truly known, nor realized that one day, he was speaking to a Demon. One who was masquerading as a Human being.

The man, or more accurately at the time, the boy that had approached him during the Night had long black hair with burgundy tips that reached his shoulders and a pair of Hanafuda Earrings.

For a moment, Michikatsu truly believed he saw Yoriichi again.

But then, the boy that couldn't be older than 15 opened his Mouth to speak.

''I'm Kamado Tanjiro.''

And then the image of Yoriichi was dispelled to see this boy give him a pleasant smile. All because he had spoken and smiled.

Everything Yoriichi had not.

He was also wearing a basket on his back, full of Charcoal. It didn't take long for him to figure out who Tanjiro was.

''Ah... are you the Charcoal Seller?''

He had heard that there was a person who traveled to towns, and when he desired so, settled in them and went on to sell Charcoal for Months to come. But what he's seeing implies this Child is that person in question.

And that this Child limited himself to a Night-Time Schedule because it's during those times when Charcoal truly is needed. No exceptions are made.

For a brief moment, he well and truly believed he was seeing a Ghost. But his tranquil days remained because the man in front of him was not Yoriichi.

He never could have been, even if he was wearing Hanafuda Earrings.

''I am. Now, how much do you need?''

Ultimately, their first meeting was an incredibly casual one. No one could have suspected anything, because Tanjiro was just that good at blending in. Incredibly likable when the Villagers saw him.

Too nice, at times even.

Be it a mask he was now wearing perfectly, or something that had remained of his Human Life, Kokushibou was unsure.

And so, Weeks to Months would pass. Everything continued in a boring, yet still happy way as Tanjiro kept talking to him whenever he sold Charcoal.

Michikatsu didn't truly dislike this life, but he would be lying if he said he didn't yearn for something more.

The Gods themselves must have hated him even then because it was then he would be attacked by a Demon and witness the deaths of his subordinates. And Yoriichi, after Ten Years, would return to his life.

And suddenly, his Tranquil days were well and truly over.

He saw Yoriichi's power. His Strength, his Skill. He wanted it all for himself.

Michikatsu, so focused on this desire for power, did not think twice before simply leaving. He left it all behind to follow the Path of a Demon Slayer.

And he was growing stronger. Truly, he was. Yet... he didn't reach Yoriichi's Level, even when he obtained the Mark. Even when he saw the See-Through World. Even when he obtained perhaps the closest Breathing Technique to the Sun. The Moon itself.

Never enough.

It's around that time he surprisingly, runs into Tanjiro Kamado again. He was on a Night Patrol around the Village he lived in when he coincidentally saw his Basket halfway empty from Charcoal.

''Oh.'' he'd said, eyes going wide.

Yet, Michikatsu's own were wide as well. And not just because of seeing a person he was familiar with.

But realizing that... well...

The person in front of him was not Human.

The Seven Hearts and Five Brains showed without an ounce of doubt that this thing in front of him was not Human.

Kamado Tanjiro, a person he had spoken to for Months, was a Demon.

And now, Michikatsu could feel it.

How eerily similar the presence of Tanjiro and Yoriichi was.

They both felt like the Sun itself.

Yet, while one felt like it, the other felt inferior to it. Like a Moon.

Tanjiro gave the feeling of a Sun, but it was so low, so weak it felt more like the Moon and it's soft if not outright cold ray.

It was like Yoriichi's own presence, so bright and burning there seemed to be nothing else but him, yet more muted. Colder in every single way.

Inferior to him.

Comparing him to an Erupting Volcano would be accurate, if only Michikatsu had ever felt the brunt of this monsters Bloodlust. All he was truly shown then and even now, was something weaker than his Brother.

''I did not expect to find you here.''

Michikatsu should cut him down. Right here and right now. He's a Demon. He must die.

But he can't, can he? He could feel the overwhelming Power this Demon has. Fighting in a Village would cause collateral damage. And even worse, much as he loathed to admit it, he may not be strong enough to win the battle.

The Demon was well aware of all this, and so he acted as if he wasn't a Demon.

''Nor have I.'' Michikatsu follows up, trying not to show he knows, ''It seems like you have changed Villages ever since I departed.''

''Indeed, Old Friend.'' the Demon purposely said, ''It was about time I moved to the next village. However, I admit, I did not expect to see you here and changed.''

The implication wasn't lost on him. It could be his Mark, certainly, but if this was a Demon, then he knew.

Demons were able to see more details of the Human Body. They could see if people were related or not by the composition of one's Flesh and Blood, the age of them by the state of one's flesh. And it also meant that by seeing the Quality of one's muscles, one could see how strong someone was.

''Worry not, I won't be doing anything... yet. If, you simply play along with me.''

As Kokushibou had learned, they were simply meetings. Talks. That was it. That was everything this Demon, who he did not know was the King of all, asked of him.

He continued training, planning to kill the Demon personally one day fast enough that no one would notice. Luring him out was impossible.

But, Michikatsu learned something as he continued training. Believing that perhaps, if he trained more, he could reach Yoriichi's level. And by reaching that Level, he could kill that Demon.

His anguished mind however, soon after, learned of something that would change everything.

Marked people died upon reaching the age of 25.

What felt like a Golden Age came to an abrupt end, and would soon become dust entirely with that knowledge.

There was no future for him anymore. He wasn't the oldest amongst the Demon Slayers, but he wasn't young either.

The difference in age between them all was by simple Months.

There was no time left for him to train anymore, there was no time for him to ever hope to reach Yoriichi's level of power he so easily seemed to obtain.

He had no time left.

And, be it a Blessing or a Curse, Kamado Tanjiro was there to listen. At this point, he was a dying Man.

He might as well go out to try and kill that Demon.

''Well, this is new. Trying to kill me now? Why?''

But, it also caused him to answer Tanjiro without hesitation now. Because what else was there to hide?

Nothing.

Which is why Michikatsu had never imagined that Kamado Tanjiro would sit down on the wooden floor and sign for him to sit alongside him.

He didn't of course. Who would be stupid enough to sit next to a Demon?

Still, the Demon spoke. Looking serene all the while.

''It seems your issue is simply that you don't have time. You can't even live the expected lifespan because of your Mark, and your mere Weeks left are not even remotely enough for you to catch up to your Twin.''

He gave a reassuring smile that should have made him vomit. Yet, it did its intended effect.

''So why not become a Demon?''

It was so deceiving, in how casual it sounded. In how normal it came out of Tanjiro's Mouth. To a point where Michikatsu initially didn't bat an eye at the words... until he did.

There were no outbursts. Michikatsu still held pride in how he acted. His only outward reaction to this was the widening of his eyes.

''If you become a Demon, you will be able to live forever.''

Tanjiro continued on as if this wasn't something outrageous to propose, looking back into the Little Garden he had poured a small time into.

''You want to perfect your techniques. I have a recent desire to turn a Breath-wielding Warrior into a Demon. So, how about it?''

His smile turned toothy as he looked at him again, his eyes turned into their natural form, showing to him entirely he was being serious.

It's only then Michikatsu realizes there is only one Demon who can create more Demons.

''You get to choose your fate, compared to many other Swordsmen or even Humans. Others do not.''

This was the Demon Progenitor he was talking to.

And, receiving such a proposition? Michikatsu found it hard to refuse. In fact, hearing about those promises... hearing about something he wanted, deep down, from the bottom of his heart...

It was so obvious.

''So, what will it be, Tsugikuni Michikatsu?

He accepted.

On that day, Tsugikuni Michikatsu was reborn as Kokushibou. Future Upper Moon One.

Prior to meeting Michikatsu, Tanjiro stopped believing he was helping people by turning them.

Perhaps because he stopped deluding himself after so many years. He was certainly helping people living on longer if they so wished, making some aspects of their lives better.

But when they ate their Families? When they became Monsters in turn that had to eat people, innocent or guilty? When they became his Servant? When they became a potential source for his Sunlight Immunity?

That wasn't saving them. Tanjiro knew that all too well. But at this point, he's so far into this, there is no going back.

And even if there was, and he somehow turned back in time...

Tanjiro doesn't believe he's capable of stopping.

He's lived on longer as the Demon Progenitor than the Human of Charcoal Sellers that then became a Demon Slayer.

Tamayo is the last person he truly tries to ''help''. Still believing it. But then... well, after what happens, there is no way for it to stick.

Tamayo hates him enough as it is.

Afterward, for many of his Demons, he turns them because he wants to. Not really out of the kindness of his Heart.

Kokushibou was a man who knew of the consequences and still accepted them. Perhaps he truly had helped him after all. But for the rest...

Douma? He wanted to turn him. Just because of his curiosity. Just because he wondered what an Emotionless man would do as a Demon and if he would fight to feel. He ended up receiving someone he utterly despised and only kept around because he grew powerful in a short span of time.

Akaza? The man had given up on life and didn't care. All the better he had a strong servant out of it that was loyal.

Hantengu? He was going to be executed, he only gave him a way out of it.

Gyokko? He was dying. Who in their right mind would refuse a chance at saving their lives?

Gyutaro and Daki? He didn't even turn them. Douma did with his permission. And their presence grated his nerves as they were a constant reminder of the fact he would never again truly be the Brother Nezuko loved.

After all, his dear Sister was too dangerous to be left alive. She was, in that sense, a chosen Demon. Not for him, but against him.

She had everything she could possibly have to oppose him. And for it, it only strengthened Tanjiro's desire to fulfill his Goals before it was too late.

Ultimately, everything stays on the tracks time had formed.

The Upper Moons still exist. The Demon Progenitor still desires to conquer the Sun for his own goals.

After all, his body still lacked aspects he desired to have from his Human Days.

The Breathing Forms. The Demon Slayer Mark...

Not reachable. Tanjiro still hopes he can at least use Water Breathing, but Sun Breathing is basically a No.

There's just something lacking in this Body that doesn't allow it. And he only discovers what much later, as technology advances.

It is a fortunate thing for every single Demon Slayers that Tanjiro lacks this important component. Whatever it is.

And so, time passes. And eventually, a Time Loop gets to be fulfilled...

The Past comes to meet The Future.

These Ancients Memories took place on a mundane day. At least, at the time, it was mundane to Sumiyoshi.

Only, it didn't remain that way.

Sumiyoshi Kamado was chopping wood on that day. It's something he'd gotten used to over the years. It basically was their only true way to provide themselves with anything else they couldn't get without Money.

It is why, he is largely surprised when his Daughter had moved and held onto his Pants.

''Papa!'' Sumiyoshi was confused as to why she approached him like that, but then, Sumire pointed to his right.

''Buh! Dah!'' knowing she was trying to tell him something, Sumiyoshi turned to look in that direction. And so, he was surprised to see a person he had not seen in two years.

Yoriichi.

The details somewhat blurred, considering everything else that happened on that same day. But, Sumiyoshi knew that it eventually led to them sitting down. Watching the Forest as they spoke.

Or, more like Yoriichi told him about many things he never spoke about previously while Sumiyoshi was there to listen.

He was touched, because that showed his trust in them.

Though he'll admit, he never did expect to hear much of Yoriichi's past. Of his Childhood, of Uta, of how he lost her and how he became a Demon Slayer in the first place.

Of how he wished to simply have lived a quiet life with his Family.

Yet, he became a Demon Slayer still and fought.

All of this, Sumiyoshi realizes, is something he will never forget. Especially once they began to reach the end of the Tale.

It's something Sumiyoshi Kamado would never dare forget.

''Soon after, I found the Demon's Progenitor.''

Sumiyoshi did not miss the hesitation that came out of his Friend when he said that. That was already a sign of something wrong.

Because Yoriichi was hesitating in telling him this. It was like he still couldn't believe it even after he'd lived through the moment. But at the same time, that sign of hesitation was so brief and muted that the Kamado Ancestor did wonder if he'd imagined it.

''And at that moment, I knew that I had been born for the purpose of defeating him.''

Then, Yoriichi turned to look at him. Not the eyes, but at his features. And Sumiyoshi realized that his friend was analyzing his face.

What he said next, made it clear he hadn't imagined his hesitation.

''The Demon's Progenitor...'' Yoriichi looked away and back at the field in front of them, ''His features were similar to yours. In fact, I had nearly mistaken him for you. But, I felt his intent. Overflowing with a desire that would swallow everything whole, like a Volcano and its Magma. Boiling and seething to consume everything. No one could escape his desire. Dare I say, I could almost compare him to the Sun.''

It wasn't just Yoriichi who felt a shiver now. Sumiyoshi did too, that he heard of this description. Someone that looked similar to him. Sumiyoshi had a hard time imagining it.

Yoriichi recounted to Sumiyoshi everything after his initial description.

The Demon Progenitor, named Tanjiro, had told to his face he had no more interest in turning Breathing Users into Demons.

''One is enough.'' he'd said.

''The Moon is fitting, is it not?'' he added.

Then, the Progenitor drew out from a scabbard his Katana. One that Yoriichi described as deceptively normal.

''I require no more than that.'' upon saying that, he'd lashed out.

The Katana was able to extend beyond it's reach, it's sharp whip being something Yoriichi knew, he could not allow to hit him.

For once in his life, Yoriichi felt the chills that death may be able to claim him tonight. But, that did not happen. Knowing he could not allow to be hit, Yoriichi went with his next attack seriously.

Hence why he saw with great surprise how the insides of the Progenitor looked. Tanjiro had Seven Hearts and Five Brains. Perhaps it was compensation for something he lacked, or perhaps it was something else entirely.

Regardless, he completed his Sword Forms and slashed Tanjiro's whole body through with his Sun Breathing and Red Blade. All the Hearts and Brains were damaged, and his neck nearly fell.

The Sword that was deceptively normal clattered on the stone pavement first, before Tanjiro's body followed suit.

Disbelief was clear in the Demon King's features as his body wouldn't Regenerate at the speed he knew he should recover from.

What surprised Yoriichi however, were the uttered words of contempt amidst his confusion.

''...my Body... still this weak...?''

It remained in Yoriichi's mind, and it was relayed to Sumiyoshi who hardly understood why such a thing was said. Without any form of context, neither of them understand why Tanjiro uttered such a thing.

But, for Yoriichi, the now was important. Because he now knew his Bright Red Blade would work even on the likes of him.

Hence why he needed to ask him something before finishing him off.

''What is the value of a Life to you?''

Tanjiro did not respond. But Yoriichi noted absolute disbelief seemed to be what crossed his eyes upon hearing that question. Until only rage was left.

Whatever train of thought was crossing the Demon's mind was unknown to Yoriichi. But from the way he reacted to the question, nothing good.

He allowed himself to glance at the Demon Girl that was by Tanjiro's side, but she made no move to help. Instead, she looked at the Injured Demon, and hope shined in her eyes.

At that moment, Yoriichi decided to finish off the Demon before the Girl. But then, a single step...

Teeth grinding hard enough that they cracked...

And suddenly, his body burst open into several pieces with incredible force.

The Swordsman had sliced as many as he could, but the pieces of flesh varied in size. So, around the 300 small pieces that escaped him, there remained enough to form the size of a Human head.

Yoriichi stood there, staring at the clothes of the Demon's Progenitor and the piece of his flesh that served as a weapon.

Left behind, were the Demon's own Hanafuda Earrings. Still pristine. Alongside it's Black and Green Checkered Haori.

His attention was however diverted by the cry of the girl, weeping as she collapsed down on the ground.

''You almost did it... but he's already overcome the weakness to beheadment...''

The girl forced out words, and a name, Yoriichi had not dared to expect as she tore at her hair.

''I wish that Filthy man had died! Tanjiro Kamado!!! ''

Absolute disbelief.

Sumiyoshi knew he was probably staring, but how could he not?! That name...!

That Demon Girl had called the Demon Progenitor Tanjiro Kamado ?! The very same Surname he and his Family held?!

''I do not know what the connection you have to that Demon is, nor do I know why he wears a pair of Hanafuda Earrings that look identical to mine. But when I asked the question to that girl, she answered the best she could.''

She did not know. The Girl assumed that the Kamados were some distant relatives of Tanjiro, and that was why they shared that same Last Name. But the Hanafuda Earrings were always there. The Demon Progenitor never was without them. Or at least, never had.

The Girl was relieved that she was temporarily free of Tanjiro's control due to his current weakened state. So, Yoriichi asked her for help. She was hesitant at first but agreed.

The Girls name was Tamayo, and Yoriichi saw she had sad eyes.

In the end, Yoriichi was kicked out of the Demon Slayer Corp due to his failure at eliminating Tanjiro Kamado and allowing Tamayo to escape. Even worse, his Brother had become a Demon.

(He didn't want to believe the Progenitor, yet he spoke the truth after all...)

Overall, Sumiyoshi noted Yoriichi's life really took a dive down. But, it wasn't his fault. Sumiyoshi voiced as much about it.

''I think I was born with special strength for the purpose of defeating Tanjiro.'' everything seemed to build up for this moment, ''But I was lacking. In the end, I failed. Because of that, many people will die. And that pains me.''

Silence remained in the air. Sumiyoshi did not know what to do or say, besides realizing his Friend had never used Kamado alongside the name Tanjiro. All he could truly do was give him a look of pity as he nearly cried himself.

And then, his own child walked next to Yoriichi and tucked at his Haori.

''Hug!''

It surprised both of them. But, Sumiyoshi realized that Yoriichi was taller than him.

''Um... would you mind holding her? She'll be happy if you lift this little one high, and you're taller than I am, so...''

Yoriichi didn't deny his request. Standing up, he went to grab the child and then:

''Kya Ha Ha!''

He held her up into the sky as high as he could, and for it, Sumire laughed with joy.

The sight he saw was impossible to describe with words. But, it made Sumiyoshi realize something. Something of importance with this beautiful sight came with sadness.

Because indeed, this was the first time he saw Yoriichi cry. And it had caused Sumiyoshi himself to cry along.

Because this? This is what a part of made him come to his decision.

The Second part, was when Suyako asked to see his Sword Forms. Yoriichi was kind enough to show her, and subsequently, Sumiyoshi himself.

Sumiyoshi watched them carefully, burning them into his memory so not one escaped. And the forms of Sun Breathing were so pretty to his eyes that he forgot to breathe.

They were stunning.

Yet, once done. Once finished and Yoriichi was ready to leave...

He gave Sumiyoshi his Hanafuda Earrings.

He realized at that moment to implication given with those Earrings alone. The fact Yoriichi was parting with them to begin with, meant that Yoriichi would never come back again.

He never did.

Sumiyoshi and Yoriichi never saw each other again.

But at this moment, as Yoriichi left? Sumiyoshi began to cry. He solidified what he felt, this promise, by declaring it aloud.

''Y-Yoriichi! You saved our lives so we will carry your Legacy!''

His Wife. His Children and even Yoriichi -who halted in his tracks- all looked at him in surprise.

''Your Life is not without value! It never has!''

He needs to make that clear before he looses the chance to. Before Yoriichi vanishes, never to be seen again.

''Don't ever think that you didn't accomplish anything! I won't ever let anyone say that about you!''

He nearly choked on the air, but he forced himself to continue.

''I will pass down these Earrings and Sun Breathing to Future Generations! I promise! One day, The Demon King himself will fall because of your Legacy!''

By the end of it, Sumiyoshi was huffing and puffing continuously. He never had spoken this way before.

And Yoriichi?

He gave a smile.

''Thank you.''

One day, no matter how long it takes, one of the Kamado's would strike down the Demon Progenitor, Tanjiro Kamado himself. They would finish the Mountain of Corpses he left behind as he lived.

One day, a Kamado would finish him and end this conflict once and for all.

And then, Kamado Tanjiro awoke. Almost immediately, his palm that was under the Futon went to his face. Sweating at what he'd seen.

''Why... do I dream this now?''

For him, it was odd. Why was he seeing Inherited Memories now? This... this had taken place Centuries ago. And yet now that he was inching closer to his own time, this came to him.

Why?

To make him feel guilty? Again?

At this rate, why would he feel guilt? He's killed so many, devoured them whole to nourish himself, and spread Demons just so he could find that elusive Blue Spider Lily or create one that is Immune to the Sun.

His own Demon Cells had long since stopped blocking his emotions. Tanjiro was a Master of his own Biology for Decades now. And it had been even more time since he could feel.

It couldn't be because of guilt. That feeling had died with him long ago.

No, he had to be seeing this for some other reason. Perhaps because of how close he was getting to his own Era?

To the day of his Birth?

The Inherited Memories he had may just be answering to how close it actually was. Soon, the Eldest Son of the Kamados would be born... in a week.

Tanjiro never realized how odd thinking of something like that would be. Until now at least.

And he wondered...

This was a Loop. He would be born, then he would be eventually sent back in time to become the Demon he was today.

But then... why was he called Tanjiro at all? Wouldn't the Kamados, Past and Present, not want to call one of their children by that name? After a Monster?

So why had either his Mother or Father allowed that?

A question he may never receive the answer to.

Groaning, he went up and out of his Futon. He wouldn't try sleeping now. It was useless, and he didn't want to even know if he could see any other Inherited Memories.

Not when it would make him see that man again. Someone he did not want to see. Ever.

Yoriichi really had demolished his Building ego that day. He was so enraged to see Yoriichi's own Superior Sun Breathing. His Superior Nichirin Blade being Red... even his Demon Slayer Mark...

He looked at those fondly. Something he lacked now, but something he truly desired to have back. One day. Because that had been his own Power once.

He truly had acted like Kokushibou at that moment. He was jealous of that Monster.

Because that man, surpassed him when he was Human. And still surpassed him when he was the strongest Demon.

If only in pure Raw Power, with the one weapon capable of doing severe damage to any Demons.

Truly a man blessed by the Gods in every single way.

''How did he even get all that power from Birth?'' Tanjiro wondered before letting the topic go.

Yoriichi did not matter anymore. He may have once when he still had his Hanafuda Earrings, but Kokushibou had recovered them when he'd finished Yoriichi off. They were back to their rightful owner.

His time would soon begin. And when it did...

Tanjiro would make sure there were no more enemies in his way.

Cruelty still happens.

On a Winter Night, when a Boy stayed overnight in a Friendly person's Home, a Demon comes home, looking the exact same.

And injects them all with his Blood while slashing and cutting.

Only one survives, while the rest of the Family perishes.

The Father's spirit see's this all but cannot do anything as one by one, his Family joins him in their horror at the fact they know of this individual.

Only one remains behind.

The next day, on a cloudy day, the boy returns to see the scene. Crying, disbelief clear in his voice and features. He cannot believe what has happened.

But, the Eldest Daughter of the Kamado's has survived the injection. As the only survivor, the boy rushes her to a Doctor. Only, she was turned into a Demon.

Everything happens similarly. The girl turned Demon tries to eat her Brother, but stops when she recognizes him. Then, a Demon Slayer comes, and tries to kill her, but is convinced otherwise.

Here comes an issue however.

The Identity of the Demon King is know to the Demon Slayer Corp. His name is known. But Giyuu doesn't outwardly react. Instead, he decides to follow the supposed Human.

He gets confirmation as he follows the Human who eventually is taken in to train by one Sakonji Urokodaki. Perhaps wearier at first of a boy with the same name as the Demon Progenitor and a sister bearing that same surname, but still caring for him as time passed by.

And here, something else changes.

When Kamado Nezuko awoke after being knocked out, she was able to almost immediately recognize the features of the attacker, on her Brother. Yet, her Childlike mind simply made her weary.

Unknowingly, this had an effect on her Body that prioritized something else.

The girl falls asleep, but instead of two years, it is simply six months.

When she awakens, it is with her cognitive faculties returned. And with an all clearer mind to know.

When she first see's her Brother, she lunges at him.

The only reason Urokodaki doesn't kill her on the spot is because of the words she spews out in rage.

''You took them away from me!''

And it only confuses Tanjiro further. But, it confirms something to Tanjiro's trainer. At which point, he wrestled her off her Brother.

''This is not the same person you believe who acted such way. This is your Brother. Completely Human.''

It said a lot that Urokodaki was able to force Nezuko still. Or the fact she reluctantly listened to his words once she calmed down.

Though Tanjiro felt hurt. Not that he'd blame her or anything, not when Nezuko mentioned how utterly similar the Demon and Human looked. But it still hurt.

Even more so because Nezuko could never truly separate Tanjiro from the Demon with his face. And so, an air of weariness remained there.

Nezuko joined in on Urokodaki's training, even if it was on a Nighttime schedule. Tanjiro wondered if it was her distrust of him. Some paranoia wondering that maybe, he was the one...

Eventually, success reaches them and they move on to their Mission. Nezuko in a box while Tanjiro walked into Daylight.

A Human and A Demon still meet in Asakusa. Tamayo is weary of the boy with Hanafuda Earrings. And yet, he still is trusted to gather Blood for a Cure for his sister, though not without a backup plan in mind.

A certain meeting between friends occurs. A fight against a Former Lower Moon, and then Lower Five happens the same, if not the confusion that rises of a lookalike.

A certain Hashira Meeting still happens, more brutal towards the sister, yet still with the Kamado Siblings victorious. Trusted by some, distrusted by others.

Loss and Gains come and go. The Infinity Train takes off to Destination. Confusion rises further. And eventually, the Upper Moons Six perish.

And then, a meeting occurs.

The Infinity Castle.

This was a location that theoretically was Infinite. If it actually was or not, remains unclear. But it was clear to everyone that the location was vast enough that it may as well be called such.

And the Power to conjure such a place was in the palms of a single Demon, gifted Blood by every single Demon's Master.

And now, it was a location that allowed for whatever Demon he desired, to be brought here.

Like now.

Nakime brought every single Upper Moon Demon to her Realm. One by one, each arrived close to each other.

They all knew what this meant, as this wasn't a scheduled Meeting. It was almost expected as well since He wanted updates on the Blue Spider Lily and if they discovered where the Ubuyashiki's resided.

But there was no planned meeting. As far as every Upper Moon Demon knew, this was not planned.

They all knew what it meant.

An Upper Moon had perished. Only a Demon of such standards dying could have them all meet like this completely unplanned.

So it made sense when they all realized it. All close to each other when they first stepped foot in the Fortress.

Their Master summoned them to inform them of that happening.

However, they were unaware of one matter.

Their Master was already present. Upside down, yes, but he was there. On top of them all. Sitting on a Desk and simply continuing his work.

None of Tanjiro's Upper Moons were aware of that fact, save for Kokushibou himself.

And so, he listened in on their conversation.

Akaza and Gyokko spoke. Then Hantengu added his own piece about the cursed Number it has been since the last complete meeting. And then, Douma came to annoy Akaza. Ultimately, the conversation they had was rather tame.

Even when Akaza punched off Douma's jaw.

But then, clearly, Kokushibou had enough of the banter and wanted to get things over with.

And so, the Upper Moon One Demon spoke.

''Lord Tanjiro... is here.''

And only then, did they feel their Masters ovewhelming presense suddenly showing. In an instant, they all noticed where he was.

Sitting upside down, next to his desk in an office. And it was filled with Maps. One after the other.

They all noticed whatever he was doing before the Meeting, must have been important.

Because he was wearing his Suit. Sans the Jacket.

The White Blouse alongside the Green Tie and brown Jeans was normal. The Checkered Vest that had Green and Black colors however, was not. Not to say it was rare to see, but usually, it was just completely Green.

And out of every Demon, only Kokushibou knew that Vest was probably made that way to match their Master's Favorite Haori.

He wondered why he actually stopped wearing said Haori, yet kept the Hanafuda Earrings. It had been a rather recent change as well.

Nearly Three Years, if he remembered right. Well, not that it mattered now to think about it.

All they heard from their master at that moment, was the sound of a pen moved along the Paper.

His gaze never wandered to them. Yet he was entirely aware that they all knelt upon noticing.

So, he decided to finally begin this Upper Moon Meeting.

''As you're all likely aware of by now, Gyutaro and Daki are both dead.''

As he said that, he crossed off a location in one of the Maps, but continued on speaking.

''The Upper Ranks of the Twelve Moons are now incomplete.''

He made his displeasure clear. For a Demon of the highest echelon to fall? It was blasphemous. Something that should have never happened.

Yet, his displeasure was not actually aimed at the Upper Moons still alive. For that matter, it didn't truly seem to be pointed toward anyone.

Except for one person, of course.

Douma could put a guess as to who he aimed the blame, and daringly, he vocalized it.

''Oh? Can that really be so? Is it because of that lookalike of yours?''

By now, news of a lookalike of their Master had reached all of their ears. Someone who had the exact same name as their Master as well. The only difference was the mark on the lookalike's forehead.

That lookalike's Mark was Red, slightly resembling Fire. Yet, their Master was a simple Scar.

''Have I given you permission to mention him?''

Anyone else would have cowered in fear, or at least shown signs of displeasure at the tone they were aimed at.

Douma grinned.

''My apologies! I shouldn't have mentioned him. Since I brought Gyutaro and Daki in, how shall I make amends? Shall I gouge out an eyeball or...''

He was cut off immediately by their Lord.

''You may keep your eyeball. It's unnecessary to me, considering what I saw... it's no wonder Gyutaro lost. Daki was too weak to handle Slayers that weren't even Hashira's, and Gyutaro got too confident after what seemed to be a victory.''

He crossed another section on the map, before removing the object in question entirely and pulling over another one.

''A shame his Poison didn't stick around after his defeat.''

For a moment, their Master went quiet. He seemed to be judging something before deciding to vocalize what he thought.

''I'll admit, I'm not surprised this happened. The Demon Slayer Corp are nothing but obstinate. Their Leader and the Hashira's will fight on and on until nothing remains of them. I can respect the sheer will that goes behind it.''

He scowled then. Not that it was visible to them, with the distance and how he wasn't facing them.

''Yet, that's exactly why I question this. Why do I still have you all around? Your purpose is simple. Eliminate the Ubuyashiki Clan, and alongside is, the Demon Slayers and find out where the Blue Spider Lily is. Yet... none of you succeeded in any of those.''

His veins throbbed, growing noticeable on his face alongside his rage. Because this was infuriating.

''The Lower Moons kept dying to the Hashira's of each Generation. To a point where they were seen as manageable goals to reach to be promoted to the Hashira Rank. Meanwhile, you Upper Moons are rarely seen on the field anymore. You're all so comfortable with your Positions, unless I give you a direct order, that most of you often won't do the two Core Tasks.''

''You're saying sad things again.'' Douma casually said, again.

''Well none of you are proving me wrong, now are you?'' was Lord Tanjiro's immediate rebutal, ''The Ubuyashiki's are not Dead. The Blue Spider Lily, not found. It's been Decades for most of you. Centuries for some others... and neither of those goals was reached.''

He circled something on the map, harder than intended. His frustration at a high point.

''I no longer know why you even exist.''

The Upper Moons can do nothing else but apologize. Most of them gave their own reasons as to why they didn't fulfil those Core Goals.

But there is one, who doesn't give an apology. In fact...

''Lord Tanjiro! Not me! I've acquired some information that will bring you a step closer to your goals! A mere moment ago I-''

''-found out the location of the Demon Slayers Swordsmith Village.'' Lord Tanjiro finished for him. Although he sounded annoyed as he finally lays down the Pen he had. And finally, his gaze wandered toward the Upper Moons.

''Did you confirm it?''

Gyokko went rather quiet. Because he was well aware he hadn't actually confirmed the information. Then again, he was relatively certain of it as well!

Not that it pleased his Master much.

''Wipe that smirk off of your face! For the first time, an Upper Moon has fallen, and I won't have their Deaths simply be brushed off like that.''

He stood up from his chair, all of them hearing the sound of the chair screeching against the floor. He took a step, and then another until his back faced his seat.

''No more waiting around. I want results within this year. Either you find the Blue Spider Lily, or you find the Ubuyashiki's. Whichever comes first.''

Or else was left unsaid. If they didn't fulfill something within this year, then they might genuinely die. Or something just as bad. They didn't know.

Lord Tanjiro wasn't done however. Though it happened in a Flash.

Because Gyokko then realized his Head wasn't on his Shoulders anymore, but on the palm of his Master. Upside down.

''Gyokko.''

Said Demon was now greatly confused.

''I require something else out of you. Something only you can do, because of how your Pots work. You will be summoned in a few months, trust me. And if you succeed... then, I will exempt you from the Deadline.'' 

Wait. Really?! That's actually really good! What luck! Though, he was curious about what that assignment would even be.

''Besides that, go confirm your information. Then go there with Hantengu.''

Then, Nakime played her Biwa once, and Gyokko's head fell down back to where his Body was. Or, close enough.

''After all, the location is bound to have a Hashira or Two waiting for you.''

Shoji Doors appeared all over the Floor Lord Tanjiro stood on, engulfing his Office entirely before he completely vanished upon the lights going out.

Just like that, the Demon King was gone from the Infinity Castle, leaving the Upper Moons to converse.

Not that Tanjiro cared as he stared back at his Maps.

''It seems that location is perfect after all...''

Now, it was only a matter of time. One that would very soon be over. Until then, he cleaned his office. He couldn't exactly leave this mess laying around.

Two Months after the Deaths of Gyutaro and Daki, Tanjiro Kamado has Gyokko summoned immediately to the Infinity Castle.

The second the Upper Moon Five Demon is in front of him, he goes straight to the point.

''I have a simple task for you. I happen to have potentially located where one of the Demon Slayers Important Strongholds are. Their Medical Facility no less.'' he pointed at a certain location on the map Circled twice over a Cross.

''Put on hold locating Sowrdsmith Village until you can confirm this.'' a pause of consideration came and went, ''And if you just so happen to meet my lookalike... bring him to me.''

There is no further explenation. Nothing. Tanjiro was as vague as possible on purpose. And then, immediately, he was dropped off elsewhere.

Nakime was following orders, but even she could tell something was off about their Master. He normally explained things better and didn't have them immediately sent off.

Yet, even she didn't receive all that much of an explanation when he left and then returned with a Demon Slayer Uniform and wounds that should not exist. It confused her greatly, yet he went to the point.

''Nakime. Send me to the location as well.''

Nakime couldn't actually question this, at risk of angering him by taking too long. She, she complied and also sent him away.

She was wholly unaware that Tanjiro Kamado's disappearance would very soon take place.

The Demon who had sent him back by accident inside a Pot, had been Gyokko after all. Granted, not him alone. That was impossible, and he'd learned it when he observed how his Blood Demon Art worked.

But he was a vital piece to fulfill it. Alongside Nezuko's own Blood Demon Art.

Tanjiro isn't entirely certain how it worked. But he could guess that because the Pots had control over the Space and Time inside them, if you mixed it in with something Destructive against it, it caused that particular kind of chain reaction.

Fascinating to think about, but horrifying to actually live through.

Either way, he waited at the location and hit.

Then, it happened.

Tanjiro and Nezuko went out there for a walk, not too far from the Butterfly Estate, but also not too close that it was in plain sight. Neither of them expected the Upper Moon Five Demon to show up there, and much less Trap Tanjiro in his pot once seen.

Nezuko fought Gyokko, and then tried to free Tanjiro by breaking the Pot with her Blood Demon Art.

The rest is History. And so, the Human forever left way for the Demon.

The Pot exploded and caused a brief amount of smoke to erupt out of it. Once it cleared away however, showed Tanjiro on the ground and wheezing for oh-so-precious air. His injuries looked to have worsened, but he otherwise was fine.

 Nezuko kicked Gyokko had enough he wheezed as she witnessed her Brother in this state.

''Brother!''

She rushed towards him to help him, but upon the touch, something felt... off. She's not sure what. But for now, she ignores it. There were more important things to do.

''Are you alright?!''

Tanjiro groaned once his breathing evened out before looking her in the eyes. Perfectly normal Red looked back at her own slitted pink.

''Yeah... I'm fine...'' he groaned in pain before his eyes drifted towards Gyokko who got his bearings back from Nezuko's powerful kick.

Tanjiro was proud to declare even his own Demons wouldn't recognize him if he hid his presence like that. Far as they were concerned, he was the lookalike.

''We... we need to retreat Nezuko.''

''He'll just follow us.'' Nezuko for her own part wasn't sure if she herself could handle an Upper Moon Five Demon now.

She had struggled alongside Tanjiro in just defeating the lowest of the Upper Moons. But this time, if they retreated, then it was fatal because it'd lead him to the Butterfly Estate.

''It's already been compromised...'' Tanjiro thinks to himself. He had been there after all.

So, he chooses to make things easier.

''Go away. You have confirmed by suspicions.''

Both Brother and Sister end up glaring at the Demon, who surprisingly to the latter, actually retreated.

All because he heard his Master's Command. Of course Gyokko had questions, but he had a mission to fulfill above all else.

Seeing this, Tanjiro had only one thing to say.

''Let's go back, Nezuko.''

Somehow, Nezuko did not feel reassured by hearing those words, in fact, she felt more in danger by hearing such words. But she complied.

Wholly unaware she wasn't leading back a Human.

Tanjiro, at this point in his life, was a Demon over a Thousand Year Old.

Such things as shame and nervousness were something a man such as himself didn't feel often, if at all anymore.

Before, because his own Biology prioritized Survival. Now? Simply because there really wasn't much shame to feel about.

Yet... yet here he was.

Back at the Butterfly Mansion since a Thousand Years. Back from a 1,000 Year Journey that changed him so much not many would recognize him.

For everyone else, it was just a few Hours. A few days at most since his ''Unlucky'' encounter with Gyokko. But for him? It was... so long ago. So so long ago...

He wonders how he even remembers them at times.

So many people he's killed. Eaten, turned, and so on. He barely remembered anyone's names or faces.

Yet... them? His memories of them actually became clearer.

And so, because he remembers them clearer every day... he becomes nervous. Which, it shouldn't, right?

He was able to immediately talk to Nezuko normally, why would it be so hard to speak to the others?

Yet, he realizes why he feels so nervous once he has to face Aoi and Kanao. Because as far as they know...

He is just Tanjiro.

It's his own disbelief at how easy it actually is to blend back in, even if he has to avoid Sunlight and find excuses that are believable and won't make anyone believe he's a Demon.

He's... not sure how to feel at how easy it is to get back in. In context, of course they wouldn't suspect him. By now, they knew ''Tanjiro'' was a Human. A kind person. One who, while similar looking to the Demon King, wasn't the same person.

Except now, they're wrong.

Tanjiro and the Demon King were always one and the same. And now, there was only one ''Tanjiro''. The Supreme Demon.

Not as a person they loved, but that they all loathed.

He was the root cause of why so much misery remained in the World. Humans weren't better, but at the same time, Demons were just worse. Magnifying the worse qualities Humans held to a point where Demons were the only fitting names for them.

He was no different.

He's nervous for the day they realize exactly who he is. Which, if he's right... will happen after he obtains his Sword. In a couple of days. Which...

He shouldn't feel nervous, but only seeing Aoi and Kanao makes him realize it will be even worse once he sees Zenitsu and Inosuke again.

Huh... to think he still cared about what they thought of him...

Absurd. Very much absurd.

He shoves those worries down as much as he can while he lays on his bed during the period of time required to finish his recovery, and puts on the Mask of Kamado Tanjiro, the Demon Slayer. The person he once was.

He fakes his recovery rate so he can be moved sooner to Rehabilitation. Soon, his Nichirin Blade would be here, and he could just leave.

Except, Tanjiro hates to admit it, he completely forgot what exactly the Rehabilitation entailed.

First, Tanjiro would like to mention he has a soft spot for the Triplets, Naho, Sumi and Kiyo, alright? Or, well, his Human self had. So of course he carried them each up into the air once he was fit again. They had fun. His disguise was still up.

But then, he's also reminded that they work here as part of the Rehabilitation. Which meant...

''Oh it hurts!''

Safe to say, it didn't go easy even as a Demon. In fact, Tanjiro swears it might even be more painful as a Demon! Seriously, Tanjiro doesn't remember stretching this hard!

Well, Sumi wasn't acting like this was a problem, so it had to be fine. Right?

''Urgh! I completely forgot how this...  Agh!''

Did something in his body just crack? That's... that's not normal, is it?!

Yet again, Sumi nor any of her Sisters looked the least bit worried. So it had to be fine... but was it? Was something cracking actually fine?

This continued on for a while. And he felt like screaming again for that long while too. He didn't... mostly.

(Naho, Sumi and Kiyo would like to say otherwise though. But they'd found it more funny than anything else. Tanjiro really had turned more dramatic than Zenitsu there)

Though eventually, as he was reaching the end with a final painful stretch, he finally asked the question.

''By the way...'' Tanjiro groaned still as he was yanked, arm and leg stretched back for the final time, ''Was a Katana delivered while I was asleep? Mine got... chipped...''

Right. A bit fuzzy there but Daki of all people had chipped his Nichirin Blade. He's not sure if that was a sign he should have eaten his words back considering he called her Weak. Then again, she really was by Upper Moon standards. Sorry not sorry Gyokko.

Then, he just hears the sound Naho makes in answer to his question, and Tanjiro feels dread.

And there, at this moment, formed itself a massive roadblock in his entire desire for a singular Sword.

''A Letter came from Hagabezuka. Do you... wanna see?'' Kiyo said that, but she was sweating a bit. And not really sounding confident.

When he was shown the letter...

Tanjiro is not sure if he should curse Haganezuka for being an absolute pain and literally dashing his plans without knowing, or compliment him for somehow conveying through Paper the most basic of words while making them somehow appear as curses.

''NO SWORD FOR YOU.''

''HATE. HATEFUL. HATRED.''

''CURSE. I CURSE YOU.''

''I'LL NEVER FORGIVE YOU''

And about many other versions of Hate, Curse, and never forgiving. Many, many versions...

Again, Tanjiro is not sure if he should be impressed or curse Haganezuka. But ultimately he stared at the Papers, practically gaping at the hate message he was sent and knew for a fact he was sweating.

''This is... bad!''

Even worse than bad! Tanjiro specifically wanted a Nichrin Blade from his Swordsmith! But Haganezuka was just complicating things!

How was he supposed to get his own Nichirin Blade before he annihilated the Demon Slayer Corp?! And it's been over two months too!

What the hell Haganezuka!

''...It just got chipped!'' Tanjiro decided to whine out his frustration.

No, Tanjiro was not crying. But he certainly felt like it at this rate. But he didn't. Absolutely not.

But then, and bless Kiyo, Sumi and Naho for this, they outright told him he could just visit the Swordsmith Village to have a word with Haganezuka. Try to convince him to create another Nichirin Blade.

''Huh? I can go?''

On one hand, Tanjiro is surprised it's even possible. Wasn't the location supposed to be secret? And yet you could just go there?

Then how come none of his Demons found it earlier?! Gyokko took a painstakingly long amount of time to even find out some form of information and then needed to confirm it still. So how did no one ever find out the place?

There had to be something else to this he was missing. There just had to be...

On the other hand, Tanjiro was positively beaming at them when they brought that up and hardly was going to think of it further when his goal was still within reach!

(Although he does internally facepalm. He has Five Brains. They all work at the same time. One of them should have considered this!)

Tanjiro promises that he will either spare those three's lives or turn them into Demons when the Demon Slayer Corp is annihilated. They did far more than they would ever realize.

Although, first things first...

He looked out at the Window where it was sunrise. Tanjiro had made a maximum and hopefully subtle amount of effort to avoid windows where the sun was seeping through, but now, he needed to figure out a good enough reason as to why he should go at Night.

He couldn't go out during the Day for obvious reasons, but he also had no actual excuses. Nezuko had one, but she could head out during the day when he carried her... through the... box...

Aha! Now there's an idea!

Suspiciously, Nezuko's Box was nowhere to be found that day. And since Nezuko herself also needed a new Nichrin Blade...

Well, Tanjiro wasn't going without his Sister.

They traveled through the Night. Or, more accurately, the Kakushi's carried them both there.

Smart.

His sight, smell, and hearing were all blocked as well. Nothing was too cautious. A shame Gyokko and Hantengu were already heading toward the Swordsmith Village, so it didn't matter. But now, Tanjiro can see why no one ever found out the location of the Swordsmiths, nor of Ubuyashiki since Kokushibou's time.

They used even tighter security, apparently.

Well, it wouldn't matter soon enough. But for now, the Demon Slayers received that particular victory.

Eventually, he and Nezuko arrived at their destination. And so, his Blindfold was taken off and the plugs as well.

Because he was at the front (and far enough from people), Tanjiro did not hide a sinister smile he gave in answer, before morphing it into a pleasant one.

''Wooooow! This place... it looks beautiful.'' for a town with Swordsmiths, he'd expected... something less beautiful. And if his nose was right...

''Hm. This smell... is there a Hotspring nearby?'' he turned to ask the Kakushi, and she nodded in affirmation.

''If you want to go for a soak however, you should first greet the chief.'' ah... a chief. He had to bow down...

Great...

Well, he'd swallow his Pride. Such a small thing in comparison to what he desired.

''Thank you very much!'' both Tanjiro and Nezuko thanked their Kakushi's. They had absolutely no idea their thanks ended up carrying much farther than they'd imagined to a certain Love Hashira.

Either way, both Siblings moved to the chief's House. At which point, they met him.

''Greetings. I'm the Chief of this Village. Tecchin Tecchikawahara. Nice to meet ya.''

What kind of name was that? Did the late parents of this old man just get that lazy at naming him?

''I'm the town's smallest and most esteemed person.''

Tanjro would never get how small people somehow found pride in their size.

''So esteemed that you should bow till your head touches the Tatami Mat.''

There was a moment when Tanjiro and Nezuko stared at each other. Except the latter realized that he had to bow until his head touches the Tatami Mat. Because that's how he'd act back then...

''Swallow your Pride Tanjiro. One bow... that's it.  One Bow and you can leave to find Haganezuka and later kill that small old man...''

Tanjiro looked back at the Chief of the Village.

With a smile on his face, he bowed his head much harsher than intended. He practically headbutted the Tatami Mat as if it had offended him.

''I'm Kamado Tanjiro!'' he faked his cheer, ''It's a pleasure to meet you!''

He completely ignored the crack he'd created. Nezuko both sighed but gave a look of amusement before giving a much tamer bow. Not quite touching the Mat, but getting close.

''And I'm Kamado Nezuko! Pleasure's also mine!''

''Oh, what a nice Young man and woman!'' the chief sounded rather pleased. But moving on from that...

As they learned, Hotaru, Haganezuka's name (which Nezuko found Cute) has disappeared. They're currently looking for him, but Tanjiro had to go Demon Slaying sooner or later. That's not accounting Nezuko was already ready to go back on the field and work herself, but couldn't because her own sword was broken.

There only was so much time before they had to be assigned another Swordsmith.

Now, Tanjiro could just accept that. Let this New Swordsmith forge his Sword. But... honestly?

He actually wanted Haganezuka to do it. He was his only Swordsmith, it was only fitting that person would forge the Sword of the Demon King. Knowingly or not.

Although, this needed to be done fast. Not only did he have only so many excuses as to why he couldn't go out into the Sun, but Upper Moon Four and Five would arrive here eventually.

He wasn't about to stop the destruction of such a vital asset to the Demon Slayers just because he wants his Sword. But at the same time... he really wants it!

Well, he could look for him. It was night...

''Our Hotspring is very good for healing the body, so just relax here.''

...ok, first Hotspring. Then he'd look for Haganezuka.

And, both Nezuko and Tanjro would admit, it indeed was relaxing. And they were left on their own. Not many would go for a soak in the night.

''Hey, Tanjiro.'' Nezuko spoke up, ''Is it just me, or do you have less scars than I remember?''

Tanjiro was about to question why she even asked that, since of course he didn't have Scars. Absolutely not.

And then he remembers that his Body was scared before he became the Demon. But then it had recovered because he was a Demon. Save for his Forehead scar. That had for some reason just never healed.

''Did I? I... don't really remember having many scars.''

A bold-faced lie that was covered with genuine confusion since Tanjiro did have a hard time actually remembering what scar he did have during this time.

Nezuko stared at him for a moment but dropped the subject. Soon after, they headed off for Dinner. Or well, Tanjiro does to keep his cover.

Nezuko doesn't need to attend, and she doesn't. She goes out to explore the surrounding area.

Except, as Tanjiro heads to the dining area, someone sees him and proceeds to rush at him.

Tanjiro makes no further mention of that unexpected meeting with Mitsuri, besides that he's left astonished this woman is a Hashira.

Then again, considering how she effortlessly spun him around for a moment... Tanjiro can't be surprised. Some Humans are just born stronger than even their own kind.

Either way, there was Dinner. During that time, she explained to him why she acted the way she did, while astounded by how much she ate. Tanjiro, as far as he remembers, has never seen a single Human needing to eat that much. Quite a firsthand experience.

Then, Nezuko went into the room, looking rather... mad.

''Did something happen?''

''Met a rude boy.'' is her answer, ''Basically insulted another Kid, and then knocked me out when I tried to protest. I'm honestly surprised he didn't kill me, considering how he seems to have forgotten the trial.''

Oh, what kind of bastard does that to his Sister now?

Certainly, Tanjiro had plans to kill said Sister soon enough. But he'd be damned if he didn't act like her Brother up to that point.

If only so he could feel what his Old Life was like for a moment longer. So that he could enjoy what may have been once his.

''Did that rude boy give you a name?''

Nezuko shook her head.

''He didn't. Though it's really impossible to miss him. Not with his eyes.''

Mitsuri, who had listened in, spoke up.

''Do you mean Tokito?''

''Toki- who?''

''Tokito Muichirou! He's a Hashira!''

Wait, Nezuko fell on a Hashira?! She-

No. Tanjiro mentally berated himself. Why's he beginning to think that way again? She'll soon be his enemy. If she died because she fell on a Hashira who apparently forgot the Trial, then that should be good for him.

One obstacle less.

''Huh.'' in the end, it's all Tanjiro says.

In the end, not much of a conversation can continue, because just then, a Kakushi arrived. Informing Mitsuri that her Blade was nearly finished being honed.

Just like that, Dinner was over.

Neither Mitsuri nor Tanjiro were truly satiated. Mitsuri outright because it just wasn't enough, though she wouldn't starve either.

But for Tanjiro, there was no satiating. He could take it in, sure, but... well, it doesn't fill him nor is there any taste. At least he doesn't vomit it out like every other Demon.

Still, before Karonji leaves, she tells them of a Secret Weapon the Swordsmith Village holds. But she herself isn't aware of what it actually is.

And now that she's said that? How could either of them not look for it?

Before leaving, he must discover this secret. Maybe it could be of use to him, in some shape or form. Or maybe not.

But he swears, he will find it.

Nezuko decided to search for this Secret almost immediately after that, on that same Night. And Tanjiro, knowing he was as limited as she was for Time, went with her.

Of course, she had some reservations about it.

''Shouldn't you be resting?''

''I should.'' even though he doesn't need it, not since a Millenium ago, ''But I want to spend time with you. We hardly spent much time together since... that.''

They both looked down after that, but both for different reasons.

''Yeah, we... we don't spend much time together...''

''Then let's make up for it now by looking for this Secret Weapon!''

Honestly, Tanjiro had expected aimless wandering for the remainder of that Night. He had not expected they'd end up finding something during the night.

In the sound of clashing Steel.

What they found, froze him in his tracks. Because never had he expected to see that man's face ever again.

On a Combat Doll called Yoriichi Type Zero, currently used against one Tokito Muichirou. The Bully, as Nezuko had pointed out.

''Kokushibou's Descendant...'' Just by looking at his Flesh and the Blood in his veins, Tanjiro was able to tell they were related, distantly it may be.

Yet, that was completely overshadowed this Living Nightmare in front of him.

What. The. Hell.

He observed as Tokito fought, his attention entirely focused on that Fight. And found it odd how it had Six Arms. He'd even voiced it aloud to Nezuko, who also wondered.

Why Six Arms?

''That Doll was modeled on an actual swordsman.''

Both Siblings practically jumped when they heard a young voice come out of absolutely nowhere. Next to Tanjro, no less. They both turned to look at who it was.

''H-When did you get here?!''

''Oh, it's you!''

Tanjiro and Nezuko both respectively said. Though the boy continued what he started.

''According to my Father, his moves couldn't be replicated unless they gave it six arms.'' he turned to Tanjiro, ''I'm Kotetsu!''

Had he really been so focused on the Mechanical Doll he'd missed some random child going next to him?

He's getting sloppy...

He put on a smile regardless, ''Nice to meet you Kotetsu!''

From what he learned, Muichirou was specifically training against the Mechanical Doll tonight because Demons fought only at Night. He was using this as practice to test out and see if he had any other shortcomings he wasn't aware of previously.

He didn't have any, as far as he observed.

The issue was that, as Nezuko had learned earlier, Tokito had forced Kotetsu to give the Doll when he'd basically said no repeatedly. It went ignored.

Because this thing was old. At this rate, it was better off being a piece of sculpture to be observed.

Not that Tanjiro would do that. Just seeing this Doll reminded him of things he'd rather forget. Yet, an idea came to mind.

This was the next best thing, but he could use the Doll as a practice dummy.

He does, once Tokito's done. And breaks one of its arms off and then tells him to dispose of his previous Blade. It inwardly infuriates Tanjiro, but he stays quiet. He has better things to do.

Though he's not sure if freezing against the Mechanical Doll the second it charges at him and getting smacked right to the face by it counted as ''better things''.

He was reminded of that damned Night.

Nezuko and Kotetsu saw as this being a Test of Power for him, considering the former also trained against the Doll. Tanjiro himself though knew very well this was more a Test of Courage.

Courage to stand up against a lookalike of that man because of how deep his fear still was present.

Thankfully, there were only two witnesses to the absolutely stupid amount of times he was knocked down by a Doll for the next couple of Nights. His own sister, and a Child.

His Pride mostly survived that ordeal. Though Kotetsu sometimes was able to crack it.

Still, fighting against that Doll sharpened back his instincts with a Blade. He hadn't used one in so long, yet doing this? It all came back naturally to him.

Even better, he'd finally used all of the forms belonging to Water Breathing again!

Though no luck with Sun Breathing...

At least he broke the Doll with his sharpened fighting skills. Something Tanjiro knows he will likely need at some point. The Demon Slayer Corp would try to kill him one day. So would Nezuko.

What surprised him, was the Sword inside the Doll.

It may look like an ordinary one, but Tanjiro can never forget the owner of that Nichrin Blade.

Yoriichi's.

Kotetsu, Nezuko and Tanjiro were so excited, they completely forgot the Sword was old. When it was unsheathed just slightly they saw how rusted it was.

Tanjiro was positively dejected.

Or at least, he initially thought so. But after Haganezuka's unexpectedly buff appearance, the Katana?

It would be polished by him. But above all else, they'd all agreed it would be Tanjiro's. His.

And Tanjiro gave a smile that absolutely creeped out all three present swordsmiths and his Sister. Though it was mostly left ignored.

And so, here he was, only a day later, reading a Book. It would soon be Night yet again.

He wondered how much longer before Hantengu and Gyokko came around.

And then, Nezuko, in her boredom as they waited, noticed the Book.

''Hm. What are you reading?'' she leaned forward slightly to take a closer look at the Book in question.

''Oh. Nothing really important.''

It really wasn't. Just the most recent version of a Book about flowers and their types. Not that it got much of Nezuko's attention.

''Why are you reading that?'' and did the Swordsmiths even have something like that here to begin with?

''It's gotten my interest. It surprises me how fascinating it actually is.''

This Book actually belonged to a Family owning a Pharmaceutical Company he currently was posing as their Son. A Son with a Skin condition that did not allow him to step under the Sun, at the risk of suffering from Horrible Sunburns.

They were kind people.

Shame for them he was using them, but when you couldn't do things yourself, you needed to use others.

No matter how much he tried to learn the subjects like Botany, Tanjiro had a hard time actually applying them.

He'd hoped that he would overcome that, like his Inability to lie but that was unlikely at this rate.

Still, that did mean he was good at other things unrelated to that matter. Not that they were prevailing at the present time.

Nezuko eyed the Book with some form of curiosity herself before her gaze wandered to the window.

''It's low enough,'' she states. And indeed, the Sun was down far enough it didn't cover the entire landscape anymore. Only pieces of it.

''You're going then?''

She nodded, ''Yes. I'm gonna talk to the Chief. See if I can get another Swordsmith to work on my replacement Blade. Haganezuka's probably going to be stuck polishing yours for a while.''

''Then have fun!'' he smiled to her.

''Mhm! I'll see you later!''

Nezuko left.

And when she left, Tanjiro dropped his smile. In fact, he stared at the Book for a moment longer before shutting it.

Tanjiro felt slightly guilty she hadn't made any progress with obtaining her New Weapon, but right now, this gave him a golden opportunity to actually sneak out for a moment.

And so, he gave a single command.

''Nakime. Tranport me.''

And in an instant, he was in the Infinity Castle.

Nakime froze for a moment when seeing what he was still wearing and his overall appearance. But his facial features shifted back to that of a Demon while the Mark on his forehead faded away.

Not waiting for a second longer, for he was unaware how long he'd have, he gave his command.

''Transport Kokushibou here. We need to talk.''

He's impatient, he knows, but he needs to know if Kokushibou has located where the Ubuyashiki's resided. At the rate this was going...

Nezuko was evolving. He'd seen it firsthand because of her Practice against the Yoriichi Type Zero.

It was only a matter of time. Time he did not desire to waste. Not while he still sought out a way to Conquer the Sun.

And so, Kokushibou was transported in front of him.

Kokushibou knew that their Master, Kamado Tanjiro, had always been unique. He almost dared to say he was in a sense a Prodigy.

It's not that he is able to learn anything in a matter of seconds. No, it's more along the lines that if he desires something, he will do everything he can to achieve it.

However, one of his desires was something Kokushibou had never imagined was truly possible.

Sun Breathing.

Tanjiro was so convinced Sun Breathing was the way to become a Demon Immune to the very Sun. And perhaps he was right. Perhaps learning such a thing truly did make you able to be Immune to Sunlight if you were a Demon.

Yet, it was impossible to learn it. Kokushibou had tried to use that same form Centuries ago and came up with nothing. And for a Demon as old as him to learn of such a thing...

He held doubts.

Yet, the Master still strongly believed he could. And even if that was impossible, he looked for the Blue Spider Lily. He would find a way to Conquer the Sun, for he desired to bask in its Light.

And then, one day, the Master gave a Mission to Gyokko. One that none of the other Demons truly knew about.

Only Hantengu would know of anything about it, all because he was meant to confirm a set of information.

Kokushibou had believed that they would all return to the norm. As close to it as possible at least. Yet, a few months after the Upper Moon meeting, he was summoned by the Master.

Imagine his surprise when he saw Master Tanjiro in a Demon Slayer Uniform. A Demon Slayer Mark fading away to show it was fake, only there because of Shapeshifting, and his Demonic features coming back into view.

''Lord Tanjiro.''

He didn't comment on it as he knelt down.

''Kokushibou. How has the hunt for the Ubuyashiki's gone so far?''

The answer was the same one as the one he'd given months ago.

''I have not... been able to... locate them.''

The Master was not surprised to hear such things. In fact, he expected it.

''I'm not surprised by that. If anything, the Demon Slayer Corp has learned to hide anything of value well, like the Village their Swordsmiths reside in. Too well for that matter.''

Kokushibou could tell that his Master knew of something more. It probably had to do with the fact he was wearing the Uniform of the Demon Slayer Corp. Perhaps Gyokko's information held more than he'd believed?

Perhaps Lord Tanjiro was more tired of the lack of results than he'd imagined? Hence why he tried to play infiltration?

If so, then Kokushibou wondered how long that could even last. Someone would get suspicious if he couldn't step into the Sun. And in terms of patience...

Kokushibou knew Lord Tanjiro was growing gradually impatient over the recent years, however, he was unsure what prompted this cause. What made him begin to rush them when previously, he was perfectly happy letting them take their time.

The Death of Gyutaro and Daki could be the answer, but that didn't feel entirely right. In fact, it was too soon as well. He'd already begun acting this way prior to their Deaths. No, there was something more to this but Kokushibou could simply not figure out what.

And so, Lord Tanjiro went to reiterate his orders.

''No matter. Keep your search going. Any sort of Leads is acceptable. But I want the Ubuyashiki's located at the end of this year. Do I make myself clear-?''

Except then, he froze.

His eyes went wider than he ever remembered them being. He remained quiet in a worrisome manner, and the silence remained to a point where Nakime herself came back in.

Then his expression went blank before a smile came to his features. A manic thing as he laughed in glee.

It made both Demons present wonder what was even going on. Before they realized that... wasn't this the first time Lord Tanjiro laughed? None of them had ever heard him laugh in any manner, and this became unsettling.

Why was he laughing?!

Nakime didn't find the courage to speak, and Kokushibou could not blame her. This was far too strange for either of them.

''Lord Tanjiro.'' and so, Kokushibou took the first step, and spoke, ''What... is it you find... funny?''

The laugh audibly began to subdue itself when he began to speak, but after he was done it practically went quiet. Yet even then, their Master smiled.

The words that came out afterward were confusing.

''It seems... I am not weakened anymore.''

Weakened? Their Master was weakened?

Kokushibou and Nakime ended up sharing a look of confusion while their Master turned his back on them. It was a curious thing to hear, but also worrisome. Since when was he weakened?

But the way he spoke...

''It seems, one of my worries was unfounded after all. It seems I will be at my strongest, soon enough.''

Had they heard that right? He wasn't at his strongest? For how long? And... and what did he mean by worries unfounded?

Nakime and Kokushibou nearly forgot their Master could read their Minds, but were clearly reminded of it when he answered them.

''I will clarify what I mean in the next Upper Moon meeting. After Gyokko and Hantengu are done with their Mission. Until then... do as I said.''

Of course Kokushibou wouldn't refuse. He would keep trying to locate the Ubuyashiki's before the end of the Year. As impossible as that truly sounded. Yet, he was curious...

''What... about... you?''

Kokushibou is very well aware that questioning their Master could be a Death Sentence, especially when questioning the wrong things or after he gave Orders he expected to be followed to the Letter.

Kokishibou faintly recalls Tanjiro calling it ''The Price to Pay for my Blood'' or something along those lines. Subservience for Immortality.

But today, their Lord felt chatty. More so than perhaps ever before. And so, he answered.

''Oh, me? Well...''

Their Master turned to face them. And so, the Demons present witnessed it in person. 

Lord Tanjiro had always had a scar on the left side of his Forehead. It was odd to see a scar on such a being of sheer power, yet it never seemed to bother the Progenitor.

Yet, this time? They both saw it.

Faintly, the Scar on that forehead began to fade. Perhaps because it was healing, yet Kokushibou doubted it. No, the reason why nearly made Kokushibou gape at his Master.

The Scar was being replaced by something. Not through Shapeshifting either. The See-Through World allowed him to see that Lord Tanjiro's Body was changing in a way such a thing would.

And so, it left for a complete view of the one thing Kokushibou had never imagined his Master would ever possess.

After all, Kokushibou had imagined that he would be the only Demon who would bear such a thing.

A Demon Slayer Mark.

Yet, here and now? Lord Tanjiro proved him wrong. And even further with his next words that held complete certainty.

''It is high time I conquer the Sun.''

At this moment, Kokushibou realized that, perhaps, Lord Tanjiro was right. Perhaps finally it would come.

The Dawn where Demons could walk under the Sun.