Thanks! A bunch of works by Yasumi Matsuno, including the Ogre Battle series, were part of the inspiration mix for this game!
For Blessing, its good if you get forced into a combat while injured. If the other unit is at full HP, there's no downside.
Like Goblin Ball and some of the Divination Cards it is a bit circumstantial, and some characters and formations will benefit from it more than others.