You whip your arms through the air, generating a 20-foot-radius vortex of swirling brimstone in a visible space within range. The cloud spreads around corners, and its area is lightly obscured. Creatures within the vortex cannot gain HP.

Each creature that is completely within the vortex area at the start of its turn must make a Constitution saving throw. On a failed save, the creature takes 2d6 fire damage.