Celestial Spirit King
The supreme ruler of the entire spirit realm, the Celestial Spirit King enforces order among all spirits and stands as the most powerful being in the spirit world by a wide margin. Interestingly, it's never been confirmed whether he even possesses a key for humans to use, let alone if he'd ever distribute one—which has made him something of a mystery to spirit mages.
Content compiled by AnimeList.moe from publicly available sources.
