Ignite

If a creature accumulates 6 stacks of Burn at once, they immediately Ignite and explode in a 15ft. radius. If you are the one triggering the explosion, all creatures of your choice within the radius must make a DEX SAVE or take [6d6] Solar damage. Creatures take half damage on a successful save. If a creature explodes in this way, they lose all stacks of Burn immediately.