Annozgoth's Arterial Leech

You evoke the blood of a creature you can see within range. Make a ranged spell attack against a creature you can see within range. On a hit the target takes 2d8 necrotic damage, and is forced to succeed a constitution saving throw against your spell save DC, on a failed save they take an additional 1d6 damage at the end of each of their turns. The target can repeat the saving throw at the end of each of their turns, ending the effect on a success. As a bonus action on your following turns, you can recover hit points equal to the d6 rolled.