Accidental Difference

Infinity Castle / Final Battle

—START—

-3rd Person POV-

They all arrived running as fast as they could.

An attack on Ubuyashiki's mansion was under siege of demons and they weren't there.

The moment the crows announced it, all hashira and Tanjiro who was with them had broken into a sprint. Each worried about the leader of the organization.

Then came the explosion.

In Tanjiro's words, the smell of smoke and burning flesh was overpowering, and left little to nothing behind, all but a figure standing in the middle.

Punctured on all sides by something and with a woman stabbing his chest.

The consequent death of the woman at the demon's hands was intercepted by a flail, smashing it's head, yet it still healed.

"It's Muzan!!" Himejima's call was one of warning and the reveal of the man they had been always after.

That made everyone who had it activate their mark and charge forward to end him.

What they didn't expect was the floor opening under them, letting them fall.

Almost all slayers had been dragged down there, into the demon's territory.

All the while, the fire burns under the moon's sky.

---

It was a fortress that spanned across infinity, Tanjiro could only see the ever changing environment as he fell deeper into the real Muzan had dragged all of them.

A few seconds ago all of them had tried to stop the attack on Oyakata-sama's state.

The flames that consumed Ubuyashiki's Manor, Lady Tamayo's attack on the demon king.

All of that and Kibutsuji Muzan had still gotten the upper hand on them sending all into a strange realm.

It couldn't be all in vain, he had trained, gotten much stronger that he was at first.

All his progress to behead that monster could not be undermined, the mark and the sacrifice it carried, saving Nezuko.

None of that will mean anything if he dies in this place.

"young Kamado" it had been after one of Tomioka-san's training battle exercises that the flame Hashira approached him. "I would like to ask you to come to the Rengoku residence with me today"

The kid didn't know why the Hashira had asked that of him, but soon enough he would figure it out. "Of course Rengoku-san"

And so they did, the run to Rengoku's house hadn't taken too long and the two were received by Senjuro.

"Ah, brother!" the little boy wasn't expecting a visit this early. "and Tanjiro-kun, what brings you here so early"

"Senjuro, dear brother of mine, I'm happy to see you well" Kyojuro greeted back. "although I would have expected you to be resting, your health is important"

"I know brother, I-" Senjuro didn't have any excuse, he simply couldn't fall asleep that day.

"It's ok dear brother, just keep it in mind" he interrupted, knowing that he would probably take a long time answering. "on another note, could you please bring the familial diary of old flame Hashiras, there is something in there young Kamado needs to know"