Draining Smite

The next time you hit a creature with a weapon attack before this spell ends, the weapon is enshrouded in a dark draining energy. The attack deals an extra 2d6 necrotic damage to the target and you regain hit points equal to the amount of necrotic damage dealt.

At Higher Levels. When you cast this spell using a spell slot of 3rd level or higher, the extra damage increases by 1d6 for each slot level above 2nd.