Transfusion

You siphon the life essence from a creature you touch, attempting to transfuse it to yourself. Make a melee spell attack against the creature. On a hit, the target takes 1d8 necrotic damage, and you get half that damage as temporary hit points, a minimum of 1.

This spell's damage increases by 1d8 when you reach 5th, 11th (2d8), and 17th level (4d8).