A swirling vortex of hot steam in a 5-foot-radius, 15-foot-high cylinder erupts in the space of a Large or smaller creature you can see within range. The target must make a Dexterity saving throw. On a failed save, the target takes 3d6 fire damage and is restrained for the duration. On a successful save, the target takes half the damage and isn’t restrained. At the end of each of the target’s turns, it must make another Dexterity saving throw. On a failed save, it takes 3d6 fire damage and remains restrained. On a successful save, it doesn’t take any damage and escapes the vortex into an unoccupied space within 5 feet of the vortex.    Until the spell ends, if the vortex isn’t restraining a creature, you can use a bonus action to move it up to 20 feet. If you ram the vortex into a creature, that creature must make the Dexterity saving throw with the DC equal to the vortex’s damage, becoming restrained on a failed save as normal, and the vortex stops moving. When you move the vortex, you can direct it over barriers up to 5 feet tall, hover it at ground level over pits up to 10 feet deep, and skim it across the surface of calm water.