Lavaburst Caltrops

Hot Feet. As an action, you can spread this bag of caltrops to cover a 5ft. square area. A creature that enters the area activates the caltrops, triggering an eruption of molten rock. The creature must make a Dexterity saving throw (DC 17). On a failed save, they stop moving and take 8d6 Fire damage. On a successful save, they take half damage and can continue moving. A creature moving through the area at half speed makes the saving throw with advantage. After activation, the caltrops are destroyed, and molten rock transforms the ground within 5ft. of where they were scattered into difficult terrain for 1 minute. When a creature starts its turn in the area, or enters it for the first time on their turn, they must make a Dexterity saving throw (DC 17). On a failed save, they take 4d6 Fire damage. On a successful save, they take half damage.