No Need for a Core?

An ancient, dreadfully powerful entity that had once been sealed away to slowly fade into oblivion is revived by a chance encounter, though in a much reduced state. A temple monk on her way home for a vacation is distracted into exploring a newly formed Spiritual Nexus due to the cuteness of its rabbit monsters, leading to an entirely unexpected chain of events. A kitsune whose death caused a goddess to pity her fate and revive her as a reincarnated Nexus Core, a land spirit of endless potential but whose life is tied to a crystal sphere that must be carefully guarded. Thrown together by a twist of luck, these three navigate a complex relationship and build their own rules to live by. But there are those who are not pleased to see the return of this ancient being.