Sektor is actually the code name for unit LK-9T9. He was the first of three prototype cybernetic ninjas built by Lin Kuei. Sektor was once a human assasin trained by the Lin Kuei. He volunteered for automation because of his loyalty to the Clan. Sektor survives the Outworld invasion because he has no soul to take.

(Personal note: Made with a Big Boa head, which is a remarkably close likeness, and the Crimson Guard Immortal body, which was certainly close enough, and at least provided the necessary chest-plate. The profile was taken from the strategy guide, and presumably from the game as well.)