The castle was originally the domain of a powerful demon who predated even Muzan’s current Upper Moon ranks. During the Heian era, Muzan discovered the demon Nakime—a woman who played the biwa (a Japanese lute). Muzan turned her into a demon, and her Blood Demon Art evolved into the ability to create and warp the . By plucking her biwa strings, Nakime can teleport anyone into the castle, rearrange its geography instantly, or trap victims in endless loops.
Shinobu confronts Doma, the psychopathic demon responsible for the deaths of her older sister, Kanae, and Inosuke’s mother. Knowing she cannot match Doma's physical strength, Shinobu executes a long-term suicide strategy, turning her own body into a lethal vessel of Wisteria poison. Following her consumption, Kanao and Inosuke capitalize on Doma's rapidly decaying body to sever his head in a chaotic, emotionally devastating finish. Demon Slayer- Kimetsu no Yaiba - Infinity Castle
The castle is a pocket dimension consisting of lamplit wooden rooms, long halls, and moving corridors. It possesses a warped direction of gravity, allowing demons to stand on walls and ceilings, creating a disorienting battlefield where up and down lose all meaning. Nakime sits at the center of the castle, surrounded by countless doors and endless halls. Every time she plays her biwa, the structure of the castle changes, scattering the Demon Slayer Corps throughout the shifting labyrinth and turning the entire fortress into a deadly puzzle. The castle was originally the domain of a