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. On a hit, the target suffers the attack’s normal effects, and the creature gains one exhaustion until the spell ends at the end of your next turn. A creature cannot gain more than one level of exhaustion from any instance of this spell. Additionally, if you hit a creature that already had exhaustion, the attack made with this spell increases by an amount of necrotic damage equal to your spellcasting ability modifier. 

This spell’s damage increases when you reach higher levels. At 5th level, the melee attack deals an extra 1d6 necrotic damage to the target, and the damage they take for having exhaustion increases to 1d6 + your spellcasting ability modifier. Both damage rolls increase by 1d6 at 11th level and 17th level.