Conflagration

You create a blast of flame in a 10ft radius, 20ft high cylinder at a point within range. Every creature within the cylinder must make a dexterity saving throw. They take 4d8 fire damage on a failed save, and half as much on a successful one. In addition, any flammable items inside or within 10 ft of the cylinder catch fire, regardless of whether they are being worn or carried. Any creature which failed its dexterity saving throw also catches fire, taking an additional 1d8 fire damage every round until they use their action to put it out, or move into an area where fire cannot exist.