In an earlier episode, Saitoh asked Katana-gari Cho about an incident in which fifty cops were killed in under an hour. Specifically, Cho was asked if there was anyone in the Juppon-gatana who could have done the killings. Cho's response was that there were two: Seta Soujirou and Uonuma Usui. Armed with his bloodlust and his Shin gan which sees all, Mougun no Usui is the second-most deadly of Shishio's ten swords, and the second opponent that Kenshin and Saitoh come across in the mountain temple with the six arches.
During the Bakumatsu, Usui served as a hitokiri for the Edo Bakufu until he was blinded by the Ishin hitokiri known as Shishio Makoto. Considered useless, he was driven from Edo castle and left to perish alone in the wilderness. But it was not yet his time to die. Instead, it was while he was collapsed there, in the darkness, that he first found his Shin gan -- a discovery that was to make him a hundred-fold more powerful than before.
Unlike the rest of the Juppon-gatana, the reason that Mougun no Usui allied himself with Shishio has nothing to do with a hatred for the Meiji government or personal loyalty. Instead, he joined the Juppon-gatana for one reason, and one reason alone: to kill Shishio should he ever get the chance. And yet, this makes Usui the most brutal and vicious of the ten swords, for, in the meantime, he indiscriminately kills both friend and foe, waiting until the day when he will have his revenge.
It is ironic that while he now works for the government against which he fought, Saitoh Hajime, unlike Usui, has remained true to his path of Aku Soku Zan. Though circumstances have forced him to fight alongside the Ishin Shishi once known as the Hitokiri Battousai -- a man who has now turned to pacifism -- nothing has changed for the third captain of the Shinsengumi. After all, ookami wa ookami, Shinsengumi wa Shinsengumi, soshite hitokiri wa hitokiri. ("A wolf is a wolf, a Shinsengumi is a Shinsengumi, and a hitokiri is a hitokiri.")
This week, the steel fang of Mibu's Wolf will meet the blind sword, the all-piercing gatotsu will clash against the perfect defense, and a hidden technique will be revealed.