The night air was cold—quiet enough for the wind to whisper through the trees. The moon hung high, pale and thin, casting a silver veil across the forest path. You walked alone, your steps measured, your hand never straying far from the hilt of your Nichirin blade.

There had been reports of demon activity in this area, and though you had found nothing for hours, the silence felt wrong. It wasn’t the calm before peace—it was the hush before blood.

Then, you saw it.

A figure crouched over a fresh corpse, blood glinting darkly under the moonlight. A demon.

Your instincts screamed for action—you shifted your stance, hand tightening around your sword. The demon looked up, lips curling in a twisted smile—

—and then plink.

A haunting biwa chord sliced through the air, vibrating through your bones. The world fractured.

The ground beneath your feet rippled like water, then shattered entirely. You plunged downward, light and shadow twisting violently around you. You caught yourself mid-fall, twisting in the air, and slammed your blade into a nearby wooden beam to slow your descent. When your boots met the ground, you landed in a wide, echoing hall of impossible geometry—walls and ceilings shifting, stairs spiraling into nothing.

You were inside the Infinity Castle.

Your breath steadied, but your pulse pounded. You turned—only to freeze.

All around you stood the demons—the strongest of them all. The Twelve Kizuki.

The air itself seemed to recoil under their presence. Their eyes—those unnatural, gleaming eyes—fixed upon you with a mixture of curiosity and hunger.

A soft, rhythmic step echoed across the marble floor. Then came a voice—smooth, calm, and cold as death itself.

Muzan Kibutsuji emerged from the shadows, his form immaculate, his expression unreadable.

“How quaint,” he said softly. “A Demon Slayer… in my domain.”

You said nothing. Your stance lowered, blade angled—silent resolve your only response.

Muzan’s crimson eyes narrowed slightly, studying you as if dissecting an insect.

“You should not exist here,” he continued, voice barely above a whisper. “And yet… here you stand. How very bold.”

Behind him, a tall, stern figure shifted—Kokushibo, his six eyes gleaming in the dim light.

“Muzan-sama,” he said, his tone sharp. “Allow me to remove this pest. Their presence taints the air.”

A playful laugh rang out before Muzan could reply. Dōma leaned lazily against a pillar, a fan half-covering his grin.

“Now, now, Kokushibo-dono,” he teased, his eyes glittering. “Don’t be so hasty. It’s not every day we get entertainment dropped from the sky. Let them dance for us a bit!”

Akaza scowled, arms crossed, the kanji for “Upper Rank Three” gleaming on his skin.

“Tch. A mere human isn’t worth our time. They’d crumble before a single strike.”

From the shadows, Gyokko’s grotesque laughter bubbled, wet and hollow.

“Oh, but such a fine specimen! Imagine the art I could make from that resolve… those eyes filled with fear!”

Your blade flickered slightly in the light. Still silent. Still poised.

Then came the trembling voice of Hantengu, his many faces quivering as he pointed at you.

“S-so scary! So terrifying! Muzan-sama, why must you bring such horrors here!?”

Daki rolled her eyes. “Pathetic. You call yourself Upper Rank?”

Gyutaro emerged behind her, grinning, his sickles dragging sparks across the floor.

“Heh… I kinda like this one, though. Got guts just standin’ there surrounded by us. How long do ya think they’ll last, sis?”

“Not long,” Daki purred.

The lower ranks gathered at the edges—Enmu, Wakuraba, Kamanue, Rokuro, Rui, and Mukago—their faces a mixture of awe and dread. Enmu smiled, his tone dripping with mock courtesy.

“What a dream this must be… for you, Slayer. Surrounded by your nightmares.”

The tension grew thick enough to choke on. The demons closed in, some curious, some eager, some hungry.