Tōkijin

Tokijin was a sword forged from the fang of Naraku's incarnation, Goshinki, and was wielded by Sesshomaru. It was supposed he used the fang of Goshinki specifically due to the mind-reading capabilities of him, and the hatred built against his (then) rival sibling, InuYasha. Tokijin is forged by Kaijinbo in 3 days. Kaijinbo ultimately becomes possessed by the sword's demonic energy and thus is defeated in battle by his own creation. The sword is ultimately broken due to stress in the manga (series continuing InuYasha).