Drain Life

You reach out to touch a creature and drain its life essence to heal yourself. Make a melee spell attack against a creature in your melee range. On a hit you deal 1d4 necrotic damage to that creature. You heal hit points equal to the amount of necrotic damage the target received. Once successfully hit by this attack a creature is immune to your use of this spell until it has completed a long rest.

This spell's damage increases by 1d4 when you reach 5th level (2d4), 11th level (3d4), and 17th level (4d4).