Blood Drain

A beam of your corrupted blood lances out toward a creature within range, forming a sustained necromantic arc of blood between you and the target. Make a ranged spell attack against that creature. On a hit, the target takes 2d12 necrotic damage, and on each of your turns for the duration, you can use your action to deal 2d12 necrotic damage to the target automatically, and be healed for half that amount, rounded down. The spell ends if you use your action to do anything else. The spell also ends if the target is ever outside the spell’s range or if it has total cover from you.

At Higher Levels. When you cast this spell using a spell slot of 5th level or higher, the initial damage increases by 1d12 for each slot level above 4th. In addition, upon reaching character level 13, the healing increases to be equal to all of the follow up damage, instead of just half.