Syphoning Smite

The next time you hit a creature with a weapon or spell attack that requires an attack roll before this spell ends, the attack gleams with Hellish Power as your attack makes contact. The attack deals an extra 2d6 Necrotic damage to the target, if the target is a construct it deals an extra 1d4 damage.

At Higher Levels. When you cast this spell using a spell slot of 3rd level or higher, the extra damage increases by 1d6 and 1d4 against constructs for each slot level above 2nd.