Bloody Tap

The caster wraps his hands with necrotic energy and touches a target ripping through his flesh and sucking up part of his life force. The targeted creature must make a Constitution saving throw. Fail causes 1d8 necrotic damage, and the caster recovers half of the damage in temporary hit points, and these hit poits disappears at the end of the turn. The damage of this spell increases by 1d8 when the caster reaches 5th level (2d8), 11th level (3d8) and 17th level (4d8).