Decaying Cut

Dark energy from the Shadowfell strengthens your weapon. As part of the action used to cast this spell, you must make a melee attack with a weapon against one creature within the spell's range, otherwise the spell fails. If the attack hits, the target suffers the normal effects of the attack and can’t regain hit points until the start of your next turn.

At higher levels: At 5 level, the melee attack deals an extra 1d8 necrotic damage. This damage further increases by 1d8 at levels 11 and 17.