The Thunder Cannon

Wonderous Item (Siege Weapon), Legendary

Invented by a Mad Artificer, this 500 pound cylindrical cannon is the logical end point of the traditional "thunder cannon" used by many Artificers. It requires ten minutes to set up proper, and 30 seconds to charge its magical blast. Once fully charged, it fires a beam of pure thunderous energy in a 10 foot wide 100 foot long line. All creatures in this line must make a DC 19 Constitution saving throw. On a failure, they take 16d12 thunder damage and are deafened for one hour. On a success, they take half damage and are deafened for one minute. If they fail this save three or more times, they are permanently deafened unless they receive the the benefits of Greater Restoration or Regenerate. Structures and unworn objects automatically fail this save, and take 3 times the amount of thunder damage. The beam can pierce any material, even adamantine or anything stronger. Once set up, it requires a DC 30 athletics check to turn it in any direction. A creature can use it's action to press a small button on the back of it, causing the cannon to stop charging and to begin reverting to it's storable form. The transformation takes 1 minute, and turns the cannon into a hand sized cube with a weight of 20 pounds. Pressing the button again will begin the set up process.