How to use blood magic effectively in battles?

[Micah]

Leech is fairly solid for low-level casters, since it's a life drain attack and will pay back most of the fatigue it costs to cast if you hit a square with 3 units in it. Rush of Strength is decent because it hits your whole army.

But yes, in general outside of L4L and the "go to hell" spells blood magic is *** in combat. So is most water magic, outside of quickness. Just the way things go.