A wave of necrotic energy crashes out from your outstretch hand in a 30-foot-cone. Creatures in the area must make a Constitution saving throw, or be burned by unholy fire. On a failed saving throw, they take 4d6 necrotic damage, and wreathed in consuming unholy fire for the duration of the spell. Once per turn, if they are hit by an attack while wreathed the unholy fire their wounds are consumed by the flames, and they take an additional 1d6 necrotic damage. On a successful save, they take half as much damage and are not wreathed in radiant fire.