Drakkthar's Soul Siphon

Spectral hands of tormented souls erupt from the ground beneath a creature you can see within range and reach out to grasp them.

The target must make a Dexterity saving throw. On a failed save, the creature takes 3d8 of Necrotic damage and is Restrained. You regain an amount of Hit Points equal to the Necrotic damage dealt. While Restrained the creature takes 1d8 of Necrotic damage at the beginning of their turn. A Restrained creature can make a Strength (Athletics) check against your spell DC at the end of their turn. On a Success, it frees itself from the grasping hands and is no longer Restrained.

At Higher Level:

When casting the spell at a level higher than 3rd, the damage increases by 1d8 for each spell slot level. (Ex. 4th level is 4d8)