Not quite what I was thinking, but I suppose that should still work alright.
Suggestions for your particular scenario:
- BE God is kind of an assist. Toggled on/off during battle, but costs RESOURCE_X if available. A certain amount of RESOURCE_X is saved for emergencies (such as Cedylle falling in battle), but as progression increases, RESOURCE_X costs decrease.
- Since BE God is an assist, there would be no need for him to have some set of equipment to keep track of, unlike Cedylle.
- If Cedylle falls in battle. BE God is automatically toggled on and uses emergency-held RESOURCE_X to transport her to the nearest shrine for both he and her to recover. Shrines are the "Trauma Inns" of this game.
Also, a better view would be to think of the player as controlling the two characters rather than being them. That way, as a programmer, you wouldn't have to give a shit which one they players view themselves as and you'd free yourself from the complications involved.