Core Overload

You overcharge a red gem to build-up and release a fiery force of destruction. Each creature in a 15-foot radius originating from you must make a Dexterity saving throw. On a failed save, a creature takes 3d10 Fire damage and is set on fire, burning for an additional 1d10 on its next turn. On a successful save, the creature takes half as much damage and isn't set on fire.

In addition, any flammable, non-organic materials and items which aren't being worn are set on fire.

At Higher Levels. When you cast this spell using a spell slot of 4th level or higher, the damage increases by 1d10 for each slot level above 3rd. The burning effect also increases by 1d10 for each slot above 3rd.