Black Knight's history is exactly the same as that of Earth-616's Silver Samurai up until the Marvel NEW! relaunch.
After Clan Yashida realized they succeeded with their Silver Samurai project, making a robotic Silver Samurai, Shin. They were able to insert some of the parts they used for Shin to revive Keniuchio. When he was revived he had part of his memory taken away, the part of his death. After he became suspicious and made accusations he found out answers from Shin's memory banks. He saw the horrors of his men leaving him to die and became enraged. He turned away from his old life and started anew.
After years of using his powers for good, he felt the call of the Ebony Blade. The mystical sword's power of creating a link with someone and teleporting that someone to its location is what started the new chapter in Keniuchio's life. He was from that point on, the Black Knight. He was quickly drafted into the new X-Force team and proved on several occasions that he is not only one of the greatest Black Knights, but a hero.