Demonic Haze

You cast a bolt of liquid-like fire at a creature that you can see. The creature must succeed on a CON saving throw or take 2d12 fire damage. If the creature fails the saving throw, it keeps taking 1d12 fire damage at the start of each turn. If it succeeds the save, then your bolt deals only half damage and sinks into the ground, turning everything in a 15-foot radius into difficult terrain that appears to roil like the sea. Any creature entering the terrain must succeed on a DEX saving throw or take 1d12 fire damage and 1d6 bludgeoning damage.