A Yōkai sword (妖刀, ようとう, Yōtō, "Demon blade") is simply a blade which possesses demonic powers. They are usually made from actual demons, or at least parts of them, such as their fangs. Some, such as Sō'unga, are actually demons whose power has been sealed inside. These weapons are relatively rare, and generally wielded by daiyōkai; however, some occasionally fall into the hands of lower-class demons. This can be dangerous for the more powerful swords, since a weaker demon can be overwhelmed and even possessed by the blade's own demonic aura. For similar reasons, humans generally are not able to wield demon swords, one notable exception being Bankotsu. In more extreme cases, a weak demon or human can even be destroyed by the overwhelming yōki of the blade, as was the case with Tōkijin and Dakki, the smiths of both weapons, Kaijinbō and Tōshū, respectively, being obliterated by the tremendous backflow of energy. It is also suggested by Inuyasha that Banryū's demonic aura would eventually kill Bankotsu.