Brimstone Barrage

You hurl a barrage of brimstone fireballs at up to 5 targets within 5 ft of each other, all within range of the spell. Each target must make a DEX save. A target takes 33(6d10) fire damage on a failed save, or half as much damage on a successful one. The target starts to burn, and the flames can't be extinguished by any nonmagical means. A target must make a CON save at the start of each of its turns. On a failed save, the target takes 10(3d6) fire damage. If this damage reduces the target to 0 hit points, the target crumbles into ash. On a success, the effect ends on the target.