Conjure Hellfire

You hurl a fist-sized ball of fire at a target that catches fire. While flames that spread from the original fire can be doused normally, the source of the fire is much harder to douse and is distinguished by its green color. You make a ranged spell attack against the target. If you hit, the creature then must make a Dexterity saving throw. On a successful save, the fire burns at their clothes and they take 1d10 fire damage as the flames die out. On a failed save, the fire hits an exposed part of their body and continues to burn for 1d4 rounds. A creature takes 2d10 fire damage at the start of each round while in contact with the fire.