I'm familiar with most -ocracies. And I don't mean a Theocracy (rule by religious officials). This would probably make more sense in a Fantasy setting (say D&D) where deities actually come down and mess around with the mortals. However if one (or more) deities took it upon themselves to rule, what would this be called?
Theocracy actually stems from Greek which means "rule by the gods":
The EtymOnline entry agrees, saying:
So the modern usage--power by "priestly or religious body" is a later usage, but theocracy literally means "rule by gods". If you want another word, however, I would suggest the neologism deiocracy or deocracy, stemming from the word deity.