Infinity Castle

The Infinity Castle is a dimensional stronghold conjured by Muzan Kibutsuji as his retreat after Kagaya Ubuyashiki's trap. It traps the Demon Slayer Corps inside, separating them as they face hordes of Lower Rank-level demons while searching for Muzan and Tamayo. The castle's layout is manipulated by its owner, Upper Rank Four Nakime, who uses her Blood Demon Art to confuse the Ubuyashikis and their mapping efforts. Kiriya Ubuyashiki, with his sisters Kuina and Kanata, leads the operation by mapping the castle with Kasugai crows, while former Hashiras Tengen Uzui and Shinjuro Rengoku stand guard.