This is a great card.. Oh man, I really liked this one. It wasn't meant to atack or be atacked, it was meant to support and you should therefore pretty much always have it behind your own troops (depends which affinity you are using). I used the blue affinity more because it didn't only heal but the units would also take 20% less damage. If you have stoneking units they take 35% less damage in total (15% from Adamant Skin and 20% from Crystal Fiend) and they get healed! Can't ask for much more. This is a card that can offer a lot if used correctly.