Nakime

 Originally in charge of controlling Muzan's hideout, the Infinity Castle (異空間無限城, Ikūkan Mugen-jō, Dimensional Infinity Fortress), she is promoted to Upper Moon Four after Hantengu's death. Nakime confronts Mitsuri and Obanai until she is restrained by Yushiro, prompting Muzan to kill her and prevent him from taking control of the fortress.