Comet Azur

Fire a tremendous comet in a torrent akin to the distant starry expanse, the place said to be the origin of glintstone. A beam of energy 15 ft wide and 60 feet long extends in a straight line from the caster. Every creature in the area of effect must make a dexterity saving throw. The area becomes difficult terrain for anyone trapped in it. If the save is failed, target is knocked prone and takes full damage. On a save, target is not knocked prone and takes half damage.