weapon name: The Unbreakable Oath
Description: This weapon resembles a wooden training katana which is incapable of cutting anything. Its attacks are mostly used for bashing or bludgeoning victims without causing lethal damage. Unless, of course, you try smashing their bones.
weapon special abilities: This seemingly useless weapon has been 'fed' the Diamond Diamond Fruit, and somehow, the wielder is able to activate its power in battle, transforming the blunt, wooden sword into unbreakable diamond. While still being non lethal, it can go up against even the strongest of lethal weapons without fear.
history: This legendary weapon has seen many hands over its lifetime, but almost always by those with a tragic history of bloodshed and terror. The original user of this sword was an infamous murderer who slaughtered 6,217 people during his career as a swordsman. Finally, the guilt of his conscious weighed too much, and he vowed that he would never again use a sword to take life, but only to protect it. To emphasize his vow, he had this weapon created. A basic, wooden training sword that could barely kill even the weakest of opponents. But he was no fool, a training sword would be worthless if he continued to battle, and so by use of mysterious, scientific means and 20 years worth of searching, he transplanted the powers of a Devil Fruit within his weapon. The sword never broke during the rest of his life, nor did his vow. Since then, the Unbreakable Oath has served as a legendary monument to those who possess a dark path, and it is viewed as a holy sword among those seeking to repent a life of bloodshed.