Enervation of Kas

You bind yourself to a nearby creature using its blood, draining its life force to heal your own wounds. Choose one creature you can see within range. If you can touch at least a drop of that creatures blood, you become bound to that creature by a thin red line of light that pulses with its heartbeat. For the duration, it must make a Constitution saving throw at the start of each of its turns, taking 6d8 necrotic damage on a failed save, or half as much damage on a successful one. The spell ends if the chosen creature is ever outside the spell’s range or if it has total cover from you.

Whenever the spell deals damage to a target, you regain hit points equal to half the amount of necrotic damage the target takes.

At Higher Levels. When you cast this spell using a spell slot of 8th level or higher, the damage increases by 3d8 for each slot level above 7th.