Incendiary cloud

Incendiary cloud is a conjuration spell that summons a cloud of smoke and embers.

Effects
An incendiary cloud spell creates a cloud of roiling smoke shot through with white-hot embers. The smoke obscures all sight as a fog cloud does. In addition, the white-hot embers within the cloud deal 4d6 points of fire damage to everything within it each round (half damage on a successful Reflex save).

As with a cloudkill spell, the smoke moves away from you at 10 feet per round. Figure out the smoke's new spread each round based on its new point of origin, 10 feet farther away from where you were when you cast the spell. By concentrating, you can make the cloud (actually its point of origin) move up to 60 feet each round. Any portion of the cloud that would extend beyond your maximum range dissipates harmlessly, reducing the remainder's spread thereafter.

As with fog cloud, wind disperses the smoke, and the spell can't be cast underwater.