Make it a spell that lasts 2 turns 
That'll make it underpowered. Right now, it's on the border between underpowered and very weak.
I've never understood the need for healing a creature. The Guardian Angel card is pretty useless because the stats are complete crap and the ability is terrible, since most of the creature control in this game is designed to kill or delay, not to damage (besides poison). On top of that, this card only heals two per turn. Two. Not five like Guardian Angel or four like Sanctuary. Two.
What are the chances that healing a creature by two health will actually save it from another attack?
Concerning the two other cards you have, one of them costs 15
, which guarantees my safety from it (let's see anyone in the meta use that) and the other one is point blank overpowered due to it being a spell. I think you need to rebalance all three of these cards.
