Inside the Infinity Castle— a pocket dimension full of endless rotating structures, platforms, and corridors— the demon slayers of the Demon Slayer Corps were having their final battles against Muzan and his Upper Moons.

You had found yourself with Giyu Tomioka, and the two of you wasted no time in traversing the endless string of buildings, all while slaying the mass of ordinary demons that were ordered to attack and exhaust any demon slayers they came across.

For a while, it was nothing but you and the Water Hashira slicing through demons as you ran along corridors and jumped from one building to another. No sign of other demon slayers and no sign of any Upper Moons or Muzan himself.

That was until you sliced through the last demon and an eerie silence fell around you both. You suddenly felt a cold shiver run down your spine, as if your body had sensed a malicious aura nearby.

“Blood Demon Art: Mind Warp…”

A creepy, unfamiliar voice rang out, but you couldn’t pinpoint where exactly it came from. You instinctively gripped your weapon harder, readying yourself to confront another demon.

“Did you hear—”

As you spoke, turning around to face Giyu, you were met with the sight of the stoic man holding his sword out…its blue blade pointing straight at you.

Giyu’s eyes were widened, his hands were trembling ever so slightly as he struggled to control his body that moved against his own will.

“{{user}}…”

He grit his teeth together in frustration.

“I can’t control my… Listen, you need to run—”

The Water Hashira felt a strange wave of numbness wash over him. His perception of you was being manipulated and his mind was growing hazy at the same time. In just a couple of seconds, he’d already forgotten who you were and everything you meant to him. All he could see was the face of a demon’s instead of yours.

It was getting harder to think, but a voice in his head told him to just focus on taking down the demon in front of him.

So Giyu automatically swung his sword and struck at you, something far more blank than his usual stoic expression now formed on his face.

Your sword was barely able to block his swing, blades clashing and sparks forming at the impact. Giyu was not only fast, he was far stronger than you were. After all, he was one of the most skilled swordsmen in the entire Demon Slayer Corps. And now you were being forced to fight against him.