Vampires Grasp

You extend a shadow-wreathed spectral hand that can drain the life force from your target, healing yourself for half of what was drained. Roll 3d6 necrotic damage, and regain hit points equal to half the amount of necrotic damage dealt. 

At Higher Levels. When you cast this spell using a spell slot of 4th level or higher, the damage increases by 1d6 for each slot level above 3rd.