Thus far the basic "attack" heal doesn't seem to be all that substantial. I just got mine to O8, but he has mediocre runes right now. So far I've seen two highly effective uses for him: 1) as part of a timeout team with Plant, Orc, Bro and Horse, and 2) paired with a good tank (like Plant) and a damage dealer like Druid. I know, folks laugh at my use of Druid, but if you can keep her alive long enough she does serious damage and strips shields. Angel Dragon both keeps her alive and boosts her damage output. She has been far outstripping my Wee Witch for damage output, and that is no small feat.