The card as it is is very strong, though maybe not for what it's supposed to be. As anti-denial card it's mediocre, as Discord usually doesn't let you get to 4

fast enough and Devourers... well those would be hurt by this card, but I heard that Darkness has some profitable ways to work against this card and before you can see the Devtal deck is gaining 4 life a turn...
The only useful application I can see is in rainbow decks against Black Hole.
On the other hand healing 4 a turn with the minor bonus of being immune to denial is pretty good and I expect to see this in many Stallbows (or other stalls for that matter).