Once per player?
So if the healer uses it on the seer/guardian once, then that's it, they can never use it on the person again? And if then, if they use it and it "fails" then they still can't use it on the same person?
I agree with Ryven, if the healer gets 50% chance hit or miss, so should the werewolves, seer, and guardian. But with all these hit/misses, it'll just drag the game longer won't it?