Kalian Blackheart

Kalian Blackheart, real name Brent P. Zeffir, is Mugen Kagemaru's older brother. Not much is known about Kalian aside from the fact that he's an incredibly skilled swordsman who taught Mugen the art of sword fighting early on. At some point, Kalian taught Mugen his signature ability - a move similar to the Skyward Strike from The Legend of Zelda: Skyward Sword that can be done without the use of a weapon. Mugen holds Kalian and his skills in high regard, and he seems to be a respectable man.