The 12 Moons are the elite-level demons that battle on behalf of Muzan Kibutsuji and the most powerful antagonist of Demon Slayer. At the top of the ranks is the extremely powerful and skilled Kokushibo, a demon with a distinct appearance wielding a katana. Fans may have noticed a distinct resemblance between Kokushibo and the legendary demon slayer Yoriichi. On top of that, the mere fact that a demon wields a katana may seem strange to fans.