Errr, maybe too much. I mean, gaining attack, and thus lives seems to have some problems... Imagine this +blessings or raged to have as much attack as I wanted. I'll rage it 6 times (since it won't die) and get an awesomely, nearly immortal creature, not to mention if I add some hp it'll respawn with it (as far as I see)...
Maybe make it respawn the next turn, or even split (changing the mechanics a bit), but right now it seems OP
BTW, anyone that liked the split idea may use it, I personally like it