Mega Man X
Commonly called simply “X”, this robot comes to fill the shoes of Mega Man in his time. X was built by Dr. Light for reasons unknown. He possessed a free will and the capability to make decisions, something no ordinary robot before him had possessed. This was what caused Dr. Light to seal him in a capsule, and what allowed future robots built by X’s design to go Maverick.
A skilled Maverick Hunter. After being destroyed and rebuilt, Zero fights with X and the other Hunters full time.
A cocky Reploid who can temporarily mimic the appearance and skills of other Reploids. He has some experience in battle but is still somewhat immature, like a kid.
Sigma is one of the Reploids Dr. Cain built from information gleaned from X himself. After going Maverick, Sigma has apparently determined that the human race is inferior to Reploids and must either be enslaved or killed. Like a persistent bug, he always returns even after he is defeated, usually in a new form, since though his bodies are defeated, apparently his programming continues to live on to cause more damage.
This is the man who uncovered Dr. Light’s laboratory during a dig. He released X and built the Reploids, which were robots built with the help of X’s design. So in a way, Cain is responsible for the Mavericks, although he certainly didn’t do it on purpose. Though he aids X and Zero, he doesn’t seem to be anywhere near as helpful as Dr. Light in the original series. This is compensated by Dr. Light’s scattered power-up capsules, which give X the aid that Cain does not.
The creator of X who lives on in the form of holograms in capsules. His capsules upgrade X’s and Zero’s armaments.
A reclusive Reploid that probably through no mistake looks like Boba Fett from Star Wars. He was apparently built by Dr. Cain, though this fact has not been confirmed. Vile has battled X and Zero on several occasions, apparently driven by the desire to eliminate the do-gooder Reploids. Although at first glance Vile seems to be a sort of right-hand man to Sigma, further study indicates that Vile actually works alone, doing as he pleases and taking orders from no one.