Silver Samurai, the illegitimate son of Shingin Harada, is a mutant with the power to charge his katana (sword) with mutant energy (a tachyon field) that enables it to slice through any known substance except for adamantium.
Harada was once the bodyguard for the international terrorist known as the Viper, but he became the head of Clan Yashida after his sister Mariko's death. He is currently attempting to pay off his clan's debts to the criminal underworld and restore its honor. Though, once one of Wolverine's greatest enemies, he has apparently impressed Wolverine so greatly that Wolverine has intrusted the care of his adopted daughter to Keniuchio.
The Silver Samurai is the leader of Japan's first super-team, Big Hero 6. The Silver Samurai is one of the few rare cases of a truly rehabilitated supervillain.