Great Unity Association, Headquarters of the Spirit Realm branch.
As a newly established organization that had only been developing for thousands of years in the Spirit Realm, it already boasted an internal membership in the trillions, with an even greater number of external affiliates. The involved races were varied and strange: humans, ghosts, demons, spirits, barbarians, witches...
If a race had existed in the Spirit Realm, it could always find some connection to it.
Of course, this wasn't because the philosophy of the Great Unity Association was so enlightened or worthy of following.
Otherwise, the Great Unity Association wouldn't have received a cold reception at the beginning.
It was purely the Will of those above.