it would be interesting to see some gnostic influence on the religion here. i am not sure how the soul will factor into the game mechanic, but i think the gnostic idea of everyone having a piece of the divine within that has been corrupted by the material earth which can be awakened by pursuing spiritual knowledge would be interesting. also, some of the dualism in gnostic teachings, a creator god who is the source of all that is good and all that is evil might be refreshing when compared to recycled Greek and Nordic pantheons you usually see in fantasy games. the rest of the pantheon could be filled out with aeons/archons and maybe a separate demiurge are removed from the divine by a flaw that is also representative of the portfolio they cover. maybe through in some Zorastroan ideas of chaos and creation to give it a little more flavor, and perhaps reinvent the traditional alignment grid that you usually see in D&D inspired worlds. otherwise, Camazotz. nothing cooler than a bat god of the underworld who represents death and uses severed heads to play basketball.