Autocombustion Arcana

Stretching your arms out wide and bringing them together in a powerful clap, arcane energy within your body causes you to explode. The flames will not harm the caster, although you and the clothes you wore upon casting will smell like smoke until they are both thoroughly washed. Each creature in a 15-foot-radius sphere originating from you must make a Dexterity saving throw. A target takes 4d6 fire damage on a failed save, or half as much damage on a successful one.

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

At Higher Levels. When you cast this spell using a spell slot of 3rd level or higher, the damage increases by 1d6 for each slot level above 2nd.