Forgive the lack of ingenuity if this is ground that's already been tread upon, but.
I was considering a game for human characters that were inhabitated with the spirit of Greek Gods of lore.
In considering I thought it might be fun to have it go multiple ways. Say someone gets Ares...and that person essentially BECOMES Ares, in personality and mind. The spirit of Ares is just so strong, that it simply overshadows the man that existed before the old God's spirit appeared. Including memories, emotions, etc.
Whereas another man may get Zeus...and finds a balance between the old God and the man that existed before the God came to that person.
You could even say a person gets 'tagged' with a god/goddess, and their willpower is simply too much, and they get all the aspects of said God but almost entirely retains their own emotions.