Onslaught's History
Onslaught was a sentient psionic entity created from the consciousness of two extremely powerful mutants: Professor Charles Xavier and Magneto. During a battle between the X-Men and Magneto's Acolytes, Wolverine slashed Magneto, and in response, Magneto ripped out the Adamantium from his bones, severely injuring Wolverine so much that even his healing factor had trouble healing him. For Professor Xavier, this was the limit. Having tolerated every one of Magneto's evil actions, even his recent actions that had killed hundreds of people across the globe in a single day, he finally snapped. He used his telepathic powers to shut down Magneto's mind, rendering him catatonic. During the psionic contact, Magneto's anger, grief, and lust for vengeance entered Professor Xavier's consciousness; commingling with every long-suppressed negative feeling the professor had endured during the last 30 years. This aggregation resulted in a separate personality within Professor Xavier, the being known as Onslaught.
Onslaught remained dormant for some time. Gradually, Xavier's frustration with his dream of mutant-human peace and harmony began to increase, exacerbated by the daily growth of anti-mutant hysteria, the deaths of dozens of mutants from the lethal Legacy Virus, and his own failed attempt to rehabilitate the mutant sociopath called Sabretooth. Xavier reached his breaking point when anti-mutant humans killed a young mutant near the grounds of the Xavier Institute for Higher Learning, the secret base of the X-Men. It was at this point that Onslaught awakened within Xavier and began to manifest himself to others.
Following an encounter with the mystically-empowered criminal called the Juggernaut (Xavier's stepbrother, Cain Marko), Onslaught invaded a government-sanctioned Sentinel base. He downloaded the current specifications for the mutant-hunting androids and erased portions of the memories of the employees working in the clandestine factory. Soon after, while hiding in Xavier's mind, Onslaught encountered the telepathic, telekinetic Nate Grey. He pulled the Professor's body from the astral plane, a feat never before achieved. Through X-Man's actions, Onslaught was able to escape Xavier's mind and move independently. After taking full possession of the Professor's mind and body, Onslaught-as-Xavier called together the X-Men. When they resisted his plan to turn them into soldiers fighting a total war against humans, Onslaught revealed himself to the X-Men and attempted to destroy the outlaw adventurers. The time-tossed mutant soldier called Bishop, remembering childhood stories of a traitor betraying and killing the X-Men, began to realize that the guilty party was Xavier as Onslaught. Bishop rescued his teammates. Taking Xavier's body with him, Onslaught escaped.
Once free, Onslaught created a childlike psionic projection named Charles to gain the trust of young Franklin Richards, a mutant possessing the latent power to alter reality. Onslaught succeeded in capturing the child despite a rescue attempt by Franklin's parents, Mister Fantastic and Invisible Woman, members of the legendary super-team known as the Fantastic Four. Now carrying Franklin and Xavier, Onslaught captured X-Man, intending to use his raw psionic power to fuel Onslaught?s plans to transform the human race into a collective consciousness. Onslaught returned to New York, reprogramming the Sentinel robots to obey his commands and form a protective circle around Manhattan, sealing off the island from the rest of the world.
The X-Men, the Fantastic Four and the Avengers, Earth's Mightiest Heroes, challenged Onslaught. Their first confrontation with the entity and his minions resulted in the rescue of a now-powerless Xavier, who retained his usual benevolent personality. Onslaught now existed as psionic energy contained within his armor. A second and final confrontation occurred at his Central Park citadel. After a number of attempts to free Franklin and X-Man from Onslaught's seemingly impervious armor, the heroes regrouped. During their next assault, X-Man Phoenix (Jean Grey) used her telepathy to turn off the part of the monstrous Hulk's mind that contained the rationality of his alter ego, Dr. Bruce Banner. The now-savage Hulk, possessed of a near-animal intelligence and unbelievable strength, battled Onslaught and tore apart his armor. The resulting explosion of psionic energy separated Banner and the Hulk, and Onslaught was left as an energy being, immune to most physical harm. Onslaught then used Franklin's powers to create a second sun that would destroy the heroes and Manhattan.
The Avenger known as Thor, Asgardian God of Thunder, master of storm and lightning, flew into the energy being, disrupting Onslaught's form. Realizing that Thor's efforts alone were insufficient to destroy their adversary, the non-mutant members of the Avengers and the Fantastic Four entered the energy field, and the Hulk-less Banner and Dr. Doom (albeit reluctantly) followed. The X-Men were unable to do likewise, as it was theorized that if Onslaught, a being of mutant origin, came to possess a mutant host, he would become unstoppable. Onslaught dissolved, seemingly destroyed, along with the heroes who had thrown themselves into the rift. The remaining Sentinels were disabled, Franklin and X-Man were rescued, and Manhattan was returned to normal. Later, it was revealed that the Avengers and the Fantastic Four did not die, as had been surmised. Rather, the heroes were reborn in a pocket universe created by Franklin. The Avengers and the Fantastic Four returned to their rightful home months later, possessing only hazy memories of their time on Counter-Earth.
Onslaught Reborn
Following the Scarlet Witch's proclamation of "No more mutants" and the subsequent depowering of most of the Earth's mutants, a large mass of energy was released into space. After awakening Vulcan and Darwin and being controlled by Xorn (who returned to Earth, fused with Collective and was then defeated by the combined efforts of the New Avengers), the ball of energy returned to Earth a second time and gained physical form as a recombined Onslaught. Immediately seeking out Franklin Richards (and failing to kill him through a mind-controlled Human Torch and Reed Richards), Onslaught quickly cornered the child in his bedroom, where Franklin once more used a toy ball as a focus to escape into a world that was for the most part an exact copy of the Counter-Earth he had created.
There, with the help of recreated versions of the Fantastic Four, Avengers and their allies and foes, Franklin battled Onslaught. The fight took them to the Baxter Building where Bucky sacrificed her life knocking Onslaught into the Negative Zone. Bucky found herself transported to Earth-616 while Onslaught remained trapped in the Zone. He was last seen floating near Wonderland curious of its purpose.
Onslaught Unleashed
As both Secret Avengers and Young Allies were investigating a Roxxon facility in Colombia, Onslaught emerged from the Negative Zone and possessed Rikki's body. He then reveals that the real Rikki had in fact died in the Negative Zone and she was just a construct made by him so he could use the energy he had stored in her as an anchor to pull himself back into the main Marvel Earth. The revelation that she had been sent to Earth solely to serve as Onslaught's tether, forced her to fight back only to prove he was wrong. Eventually, Rikki had Gravity kill her so that Onslaught could not return and destroy Earth.
