As you hold the staff out, a huge explosion of black flames shoots forth from the blackened crystal. Each creature in a 40-foot cone must make a Dexterity saving throw using your spell save DC. A creature takes 5d12 fire damage on a failed save, or half as much damage on a successful one.

Higher Level Casting: When you cast this spell with a spell slot of 5th level or higher increase the fire damage by 1d12 for each spell slot above 4th level.