Charliotte's Blazing Longstrider

You touch a creature. The target's speed increases by 10 feet until the spell ends. In addition, until the end of its next turn, the target’s movement leaves a trail of fire behind it that lasts for the spell’s duration. The trail of fire deals 3d6 damage (Dexterity save for half) to any creature not under the effects of this spell who begins its turn in the fire or moves into or through it.

At Higher Levels. When you cast this spell using a spell slot of 2nd level or higher, you can target one additional creature for each slot level above 2nd. In addition, the damage of the fire increases by 1d6 for each slot above 2nd.