Demon Pyre

You focus on your inner flame and generate a ball of chaotic fire in your hand, you then throw this ball at a point you can see within range. The ball then explodes in brimstone and lava in a 20’ sphere. Creatures in this sphere make a Dexterity save or take 6d6 fire damage, half on a successful save. This explosion will also ignite flammable objects in the area that aren’t worn or carried. Then, the lava from this explosion settles on the ground beneath this sphere and remains until the start of your next turn. A creature starting their turn in this lava takes 2d6 fire damage.