Attack! Mega Man X

Robots Mega Man X (Rockman X) and Zero battle against an evil robot named Sigma.

Mega Man X video game in manga form. Repliroids, developed to protect humans, have begun to attack humanity as being superior to it. However, the developer of the Repliroids has anticipated the worst and left the Repliroid who is constantly evolving to protect humanity, Rockman, as a last trump card.