Void Flame

A horizontal wave of black fire roars through  from the deepest trenches of the Void in a location you specify. Each creature in a 10-foot-radius, 30-foot- long cylinder centered on a point within range must make a Dexterity saving throw. A creature takes 5d6 fire damage and 5d6 necrotic damage on a failed save, or half as much damage on a successful one.

At Higher Levels. When you cast this spell using a spell slot of 6th level or higher, the fire damage or the radiant damage (your choice) increases by 1d6 for each slot level above 5th.