A bright streak flashes from your pointing finger to a point you choose within range, where it slowly ignites the air itself with phlogiston. Each creature in a 20-foot-radius sphere around the target point takes 4d6 fire damage, or half damage with a successful Dexterity saving throw. Every target that takes damage takes the same amount of damage again at the start of your next two turns unless it uses an action to put out the flames on its clothing, hair, and other accoutrements. Flammable objects in the area that aren’t being worn or carried are also ignited.