Tzeentch's Firestorm

You create a bolt of green fire that fly's toward a point of your choice. Each creature in a 20-foot-radius sphere cantered on that point must make a Dexterity saving throw. A target takes 8d10 fire damage on a failed save, or half as much damage on a successful one. The fire spreads around corners. It ignites flammable objects in the area that aren’t being worn or carried.