Combustion Plane.

The caster spins once making fire shoot out in all directions in a 35 ft by 35 ft circle, lighting the ground on fire. The original flames that shoot out deal 5d4 fire damage to all creatures in its range, and the ground fire does 1d4 fire damage per turn that a creature is in the fire. The flames on the ground last for 3 rounds (Unless they are put out).