Daedalus

Weapon (light ballista), very rare (requires attunement) This weapon requires Str 15 to wield properly. You gain a +1 bonus to attack and damage rolls made with this magic weapon. This weapon scores a critical hit on a roll of 19 or 20 and deals 2d8 piercing damage on a hit. When you roll a 1 on an attack roll with this weapon, it misfires. Roll the damage as normal and you take that damage instead. A weapon of incredible power that is difficult for even the strongest of warriors to control.