Blood Eater

You channel forbidden magic which causes your hands to manifest small mouths and they hunger, ready to deliver an attack and consume the blood of the target. Make a melee spell attack against one creature within 5 feet of you. On a hit, the target takes 1d10 necrotic damage. After you make the attack, your hands are satiated and you gain hit points equal to half of the damage that was rolled. If the target dies, you cannot gain more points than the target had remaining.

The spell's damage increases by 1d10 when you reach 5th level (2d10), 11th level (3d10), and 17th level (4d10).