Demon Slayer: Kimetsu no Yaiba Infinity Castle

The night begins with Muzan striking back. After the Hashira Training, the Demon Slayer Corps believe they are prepared, but Muzan seizes the advantage in an instant. With a single move, he drags every Slayer into his domain — the Infinity Castle, a nightmarish fortress of endless corridors and shifting walls. Its living architecture twists constantly, tearing the group apart and forcing each of them to face the enemy alone.

Tanjiro and Giyu are thrown into a brutal battle against Akaza, the Upper Rank Three who once killed the Flame Hashira. Their clash shakes the castle itself — fists against blades, rage against resolve. Tanjiro pushes past his limits, glimpsing the “Transparent World” that allows him to read Akaza’s movements. Yet in the middle of this violent struggle, fragments of Akaza’s past as a human resurface, revealing the grief and tragedy that shaped the demon he became.

Elsewhere, Zenitsu is confronted by Kaigaku, his former senior in the Thunder Breathing style who betrayed humanity and turned into a demon. The fight is bitter and personal. Kaigaku mocks Zenitsu as weak, but Zenitsu refuses to bow. At his breaking point, he unleashes a technique of his own creation — the hidden Seventh Form — proving his strength and silencing the shadow of his past once and for all.

In another part of the castle, Shinobu Kocho finally comes face to face with Doma, the Upper Rank Two responsible for her sister’s death. The battle is tense and merciless: Shinobu’s speed and poisons collide with Doma’s icy powers. She fights with every ounce of determination, but his strength is overwhelming. In the end, Shinobu is consumed, yet even in her death she does not surrender. Having filled her own body with a massive dose of poison, she plants the seed of Doma’s downfall, leaving him weakened for those who will follow.

Meanwhile, the other Hashira and demon slayers are scattered through the fortress, locked in desperate battles of their own. Rooms collapse, staircases twist, and the very floor shifts beneath them — the Infinity Castle itself acting as an enemy. Outside the chaos, the Ubuyashiki children and their crow allies race to map the shifting labyrinth, guiding the Corps toward Muzan’s hidden chamber.

By the end, victories come at an unbearable cost. Friends and allies fall one after another, their sacrifices carving a path forward. Tanjiro, Giyu, and Zenitsu emerge from their battles alive but scarred, carrying both triumph and grief. Muzan, however, remains untouched, watching from the shadows of his endless fortress. The Infinity Castle continues to twist and breathe, pulling the survivors deeper into its heart, toward the final confrontation that will decide everything.