In the "X" series, the saga takes a second breath. The story starts several years after the "classic" games in a futuristic world where humans and machines coexist. . . .

Dr. Thomas Light The creator of X, a famous scientist long dead now, he appears in a holographic form, hidden in capsules, to help Mega Man.

Dr. Cain The archaeologist who discovered Light's laboratory and unearthed X. He later used its advanced technology to create a new generation of autonomous robots: the reploids.

Mega Man X X is a vigilante robot able to think and take its own decisions.

Zero A mysterious wandering robot designed well before the reploids. He was found and defeated by Sigma and reprogrammed by Cain. Now, he fights alongside X the reploids who turned against humans.

Sigma One of the reploids created by Cain, he has suddenly turned berserk shortly after his duel with Zero. Since then he is the recurring villain, determined to exterminate all men and robots who dare oppose him.