With a stony exterior and a sarcastic demeanor, Rockslide trains to be one of the heroic X-Men and protects his teammates with his immense strength.
From Bully to Hero
Believing the way to earn respect was through strength, Santo Vaccarro uses his larger frame to bully other students, and believes he would eventually become a professional athlete. When he enters puberty and his mutant power begins turning his body into stone, he’s not allowed to participate in athletics, his body becoming something he resents.
As such, Vaccarro transfers to Charles Xavier, AKA Professor X’s Institute of Higher Learning, a school for mutants run by the X-Men, and quickly befriended his roommate Julian Keller, AKA Hellion. Both natural troublemakers, they gravitate toward the Hellions training squad led by reformed Super Villain Emma Frost, now a member of the X-Men.
Vaccarro’s swagger and sarcastic humor sometimes alienates him from the other students. During a school break, Vaccarro and the Hellions visit California, where the enigmatic Kingmaker offers them their hearts’ desires. Vaccarro, now called Rockslide, chooses to become a contender in a wrestling league for superhumans, but when Kingmaker asks them to commit crimes in exchange for their wishes, Rockslide is one of the first to refuse, taking his first step toward heroism.
At Full Strength
Rockslide’s body is completely comprised of rock, possessing the appearance and physical properties of stone, including greatly enhanced durability, as well as superhuman strength (Class 75) and stamina.
He can detach portions of his body, launching them as stony projectiles, which can be manually reattached at will, but cannot be controlled while separated. He can reconstitute his body from nearby rock after being physically shattered, his body assuming the properties of whatever rock used to rebuild. He has learned how to shatter himself at will, reconstituting himself within moments.
Rockslide’s metabolic processes, such as his need for food, fluid and rest, have not been revealed.
When William Stryker’s mutant-hating Purifiers attack Xavier’s school after most mutants were depowered, their attack leads to the death of Rockslide’s close friend Brian Cruz, AKA Tag and many others. Feeling like he could have done more to protect his former classmates, Rockslide becomes protective of his other teammates, defending them as much as possible against their foes.
Donald Pierce, mutant-hating cyborg and longtime foe of the X-Men, poses as Scott Summers, AKA Cyclops, and tricks Rockslide and his fellow teammates, resulting in the loss and seeming loss of his friends Nicky Gleason, AKA Wolf Cub, and Sooraya Qadir, AKA Dust, respectively. Rockslide’s friends.
Rockslide experiences a berserker rage against the murderous Pierce, but he’s stopped by sound advice from veteran X-Man Logan/James Howlett, AKA Wolverine.
Strength Lies In Union
Rockslide becomes close with his teammates, the Hellions and the New X-Men, including Hellion, Tag, and Victor Borkowski, AKA Anole. As one of these New X-Men, Rockslide receives training from Wolverine and Peter Rasputin, AKA Colossus. He sees combat alongside the X-Men against foes such as En Sabah Nur, AKA Apocalypse, and Bruce Banner, AKA the Hulk, even fighting the green behemoth in hand-to-hand combat.
When an insane Wanda Maximoff, AKA Scarlet Witch, stripped most mutants of their powers in the “M-Day” incident, there were only 198 mutants left with powers. Not among the depowered, Rockslide was traumatized when mutant-hating zealots, the Purifiers, murdered dozens of his depowered classmates, including his close friend Tag. Vaccarro felt he had failed for not protecting those in need. Frost tested the remaining powered students through an all-out brawl; those left standing, including Rockslide, became X-Men in training. He trains with Wolverine and Colossus, and goes up against many of the X-Men’s frequent foes like Apocalypse.
During a battle with Reality-811’s mutant hunting robot Nimrod, Rockslide was shattered and believed dead. To the amazement of all, himself included, Rockslide reconstituted himself completely. A similar incident occurred when fighting the sorcerer Belasco in limbo, AKA Otherplace, and when Rockslide reconstituted himself from local stones, his body assumed the lava-like properties of the realm itself. Upon returning to Earth, he replaced the limbo stones with standard rock. Around this time, Rockslide and teammate Anole began a close camaraderie.
After the X-Men disband, Cyclops recruited Rockslide, Wolf Cub, Dust, Blindfold, and Ink to be a new team of heroes. Their first mission was to hunt former New Mutants who were reforming the Brotherhood of Evil Mutants. The team experienced a few battles and lost Wolf Cub in the process. Then they learned that Cyclops was actually the mutant-hating cyborg Donald Pierce in disguise who caused Wolf Cub’s death. Rockslide and the heroes captured him and reunited with the X-Men in San Francisco.
He stayed on the team, helping them against the Y-Men and the Neo. When Rockslide came into contact with Pierce later, after Dust seemingly perished at the villain’s hands, Rockslide experienced a berserker rage and took it out on him. Though Wolverine was there to remind Santo that killing wasn’t going to satisfy him in the way he thought. When Dust appeared to have survived, Santo was entirely relieved to have her back.
At Simon Trask’s anti-mutant rallies, Rockslide and Hellion teamed up to encourage riots. He later went up against Illyana Rasputin, AKA Magik, who was seeking her Soulsword and defeated him. After collecting himself, he met with the X-men and was sent to Limbo with a magic-resistant team. Rockslide added the terrain in Limbo to his body structure which helped him fight against Colossus and Wolverine who were both being controlled by magic.
When the Inhumans released their Terrigen Mist, it killed many mutants. Cyclops recruited those left, including Santo, to capture the Inhumans. Though it led to Cyclops’ death, it opened up negotiations with the Inhumans.
Santo opposed Nathaniel Grey, AKA X-Man, when the powerful mutant wanted to change the world and he went through with it but disappeared the X-Men, including Santo, who were in his way. They were placed in another realm where they had no memories but it was a utopian society that finally fulfilled Professor X’s vision of peace. In this utopia, Rockslide was a student of history, albeit revised. Santo, like the others, were eventually permitted to leave when X-Man realized what he had created wasn’t freedom nor peace.
When Professor X, Max Eisenhardt, AKA Magneto, and Moira MacTaggert, AKA Moira X, established the mutant island nation-state of Krakoa, thanks to Krakoa, Santo joined his fellow brethren there. He befriended Summoner from Arrako, the sister being/planet to Krakoa, but Summoner ultimately betrayed and killed him. He perished in Otherworld, which meant that Krakoa’s resurrection team, the Five, could not bring Santo back in the typical manner, making his death final. However, what remained of Santo within Cerebro was an amalgamation of Santo’s from across the multiverse, which was used to create the next version of him. Mutant Lorna Dane, AKA Polaris, honored the original Santo by taking his remains and using them to create a portal.