[Demon Slayer] The Four-Hundred-Year Wait Is Over, Welcome Back, Moon Pillar

[Blurb]

The unserious titles: "The Warring States Veteran Returns to His Old Trade," "A Retired Pro Player Gets Called Back to Work," "Five Hundred Years After the Runner-Up of the First Pro Tournament Quit, He Returns to Play in the Resurrection Match," "Damn Moon Pillar Is Pretending to Be My Most Revered Senior Kokushibo," "Four Hundred Years of Diligent Service, Then One Nap Sends Me Back to Square One," "Version 1.0's Top Carry: Guaranteed Win If You Don't Feed," "When the Third-Ranked Player Who Quit the Game Returns with the Absurd Stats from His Version"

The serious title: Reborn as Someone Else

[The Serious Blurb]

Michikatsu Tsugikuni

The twelfth head of the Tsugikuni family, a prestigious Warring States clan. The second most powerful genius swordsman of the era. The Moon of the original nine Hashira of the Demon Slayer Corps. The elder twin brother of Yoriichi Tsugikuni, inventor of the Breathing Style, and founder of the original Breathing Style, Moon Breathing.

But behind his glory lay the deepest darkness. He was seduced by Muzan Kibutsuji and betrayed the Demon Slayer Corps, cutting off their leader's head with his own hands. From then on, he entered an endless night and became the first of Muzan's Twelve Kizuki: Kokushibo, Upper Rank One.

From the Warring States era to the Taisho era, four hundred years passed. The Upper Ranks changed repeatedly, both in membership and order, but Kokushibo remained firmly in the position of Upper Rank One. He was the only Hashira in centuries to betray the Corps, and the most vicious and powerful demon beneath Muzan. More than a hundred Hashira had died by his hand.

The Demon Slayer Corps could not even learn what he looked like or what he was called, because no one who encountered him ever returned alive. The last reliable report identifying him was from 386 years ago.

Because of his betrayal, and the years-long campaign to hunt down swordsmen who knew Sun Breathing, the original Sun and Moon Breathing Styles were both lost. No one would ever again behold the power and brilliance of the Sun, like an eternal blazing sun, or the tranquil elegance of the Moon, like a thousand-year-old moon. He was the sole and final user of Moon Breathing in those four hundred years.

All right, that's enough about Kokushibo's life and history. Now Michikatsu Tsugikuni has a big question:

If Kokushibo is Michikatsu Tsugikuni, then who am I?

And how did I end up in this world four hundred years later?

[Short Skits]

1

Master: Hashira are the Demon Slayer Corps' most dependable strength. The selection and training of Hashira are fraught with hardship, and survival is a long shot. Becoming a Hashira takes more than hard work. It takes talent, and countless drops of blood and sweat. Of the ten thousand swordsmen we train, only one can become a Hashira...

Kyojuro: Master, I found one on the roadside.

Master: ?

2

Master: Muichiro, a relative of yours has joined the Demon Slayer Corps.

Muichiro: Is it a distant cousin or something?

Master: No, your great-great-great-great-great-great-great-great-great-grandfather.

Muichiro: ?

[Important] [Reader's Guide]

* Michikatsu Tsugikuni is the central character. No romance. There is a brotherly bond between the Tsugikuni brothers, a grandparent-grandchild bond between the Moon and Mist Hashira, and he's friends with everyone.

* Big Brother is disabled, missing his right arm and using a prosthesis. He has amnesia from the start, is partly disfigured, and is ill. He's got a whole pile of debuffs.

* Incorporates Sekiro elements. His prosthetic arm can be thought of as a shinobi prosthetic.

* A mountain of original headcanons, heavily altered plot, out-of-character characters, and a scrambled timeline. Muzan has a brain. There are original characters, plotlines, and settings, and the story does not follow the original work or guidebooks. Not recommended for fans who are overly attached to any particular character.

* Big Brother arrives very early, and the timeline stretches on for a long time. Many years pass between Tanjiro joining the Corps and the battle against Muzan.

* A Warring States antique retires with the Demon Slayer Corps, occasionally killing demons, looking after kids, and enjoying a happy life full of bickering and fun.

* There are descriptions of his appearance. Big Brother is a handsome man whose beauty grows on you.

* Please don't compare combat strength or nitpick the lore. The author is a huge fan of Big Brother. Here, he's a genius swordsman, the Moon Hashira Michikatsu is simply powerful, a living sword saint and an incarnation of the Moon God. His overwhelming strength defies reason. Even crippled, he can fight an Upper Rank head-on. If you can't accept that, don't read.

* Big Brother loves children dearly, but has no outlet for all that older-brother energy, so he directs it all at the Tokito Brothers and Tanjiro.

* Michikatsu in this story is composed, cautious, serious, and gentle. He speaks slowly, appreciates elegance, and was raised with strict manners. He's got older-brother vibes through and through.

* The Moon Hashira in everyone's eyes: powerful, dependable, taciturn, rarely shows emotion, cares for his juniors, and seems cold on the outside but is actually gentle.

Theme: Reborn as Someone Else