Muramasa Blade

A F12 weapon focus nodachi. It was forged by Masamune's student Muramasa as a challenge to his teacher that Muramasa is the better smith. He put all of his effort into it, including his blood and soul. As he poured all his evil into the forging process the weapon became infused with 4th world magic. The magic was so strong it could open a rift into the plane of an unnamed Yama King. Muramasa's soul became tethered to the sword and he became a gatekeeper of the shadow realm, his soul forever bound to The Demon Blade. The sword is impossible to bind to any awakened as it is already bound to Muramasa himself. The nodachi is currently under the secret protection of Hideo Masamune, one of the last descendants of the Masamune bloodline.