Hoping to create a powerful mutant he could control, the villainous Mr. Sinister engineered Nathan Summers' birth to Scott (Cyclops) Summers and Madelyne Pryor. But when Nathan became infected with the incurable Techno-Organic Virus, his father sent him into the future for treatment.
Nathan lived for decades in the future, becoming a hardened warrior and expert leader. He then returned to the present, vowing to prevent the horrible future he had lived through. He often fights alongside the X-Men, but occasionally works alone or with his own hand-picked teams of mutants.