Draining Smite

The next time you hit a creature with a weapon attack before this spell ends, the weapon is wreathed in shadow. The attack deals an extra 2d6 necrotic damage to the target, and the target’s maximum hit points decrease by an amount equal to the necrotic damage taken until it complete a short or long rest.

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.