The Infinity Castle's range seems to extend beyond its already incomprehensibly large area. Due to the absence of sunlight within the fortress, demons are able to reside in the Castle full-time, even the during daytime. The infinity castle has demons that live there temporarily, and sometimes permanently, like the uppermoons who live there whenever they aren't on missions or hunting. Muzan and Nakime are the 2 in control of the Infinity Castle, Nakime listens to Muzan and Muzan gives orders.