Field of Reaping

You create a shadowy field that reaps escaping life force in a 30-foot Cube originating from a point within range. A creature Hostile to you in the field when it appears, or when it enters the field for the first time on a turn or ends its turn there, is cursed until the end of its next turn. While cursed, the first time the creature takes damage during a turn, it takes an extra 1d6 Necrotic damage, and a creature of your choice within the field that isn’t cursed by it regains a number of Hit Points equal to the Necrotic damage taken.

Using a Higher-Level Spell Slot. The damage increases by 1d6 for each spell slot level above 5.