Blazing Nova

As an action you release a burst of solar energy. Each creature in a 30-foot-radius sphere centred on you must make a Dexterity saving throw. A target takes 6d6 fire damage or 6d6 radiant damage on a failed save (up to DM discretion-any combination of fire or radiant damage as long as the total is 6d6), or half as much damage on a successful one. This damage does not effect the caster. When cast at higher levels the damage increases by 1d6 per level.

The fire spreads around corners. It ignites flammable objects in the area that aren't being worn or carried.