The actual spell description and what is says here are different. Once mem'd, the spell says:
Spell Effect: A direct damage spell which hits it's target, and heals the target's target.
Slot 1: Decrease Hitpoints by 4270
Slot 2: Skeleton Illusion
NOTE ON EFFECT: It heals whoever is target when spell LANDS. Not when you start casting. I assume it's the same for all the spells like this.