Ebon

Ebon Ha Ken, AKA Sir Shugyu, is a human from the world of San Fransokyo. Loosely based on Ebon Samurai of the original Big Hero 6 comics, Ebon is a technologically-enhanced samurai with not only stealth and martial arts training, is a master of teaching shugyu, and possesses a 7.2ft lightsaber-like katana similar to Sephiroth's Masamune, which he can also wield with one arm, capable of using plasma to slice through partially anything. The katana can only be wielded by him because it's programmed to only respond to his DNA.