An
Italian-American mutant from Boston, Santo Vaccarro is sent to the
Xavier Institute, where he befriends
Julian Keller and the would-be
Hellions. He is originally advised by
Iceman, but is selected by
Emma Frost to be part of her prized Hellions squad. Santo and the rest of the Hellions go on to win a field tournament and are declared the best squad at the end of the school year. During Rockslide's summer vacation, he and the Hellions encounter the
Kingmaker, who temporarily grants each of them a wish. Rockslide's wish is to become a world-class wrestler. When the Hellions refuse a permanent deal with the Kingmaker, the Kingmaker shatters Rockslide's body with a laser blast. Hellion uses his
telekinesis to reassemble Rockslide, and together the Hellions defeat the Kingmaker.
Decimation Rockslide is one of 198 mutants who retain their powers following
M-Day, when the
Scarlet Witch removes the powers of most of Earth's mutants. The depowered students and staff are intended to be sent home, but
William Stryker bombs their bus, killing Rockslide's friend Brian Cruz (
Tag), among others. Rockslide laments not being able to save his friends. With the mutant population drastically decreased, the
Sentinel O*N*E* Squad is sent to watch over the X-Mansion, which houses the remaining mutants.
Emma Frost places the remaining students in a battle to determine who will be assigned to become a group of in-training
X-Men. Santo makes the team and begins training to become an X-Man. The X-Men learn that William Stryker had been working with the Sentinel
Nimrod, who they decide to track down and destroy. During the ensuing battle, Rockslide's body is destroyed after he takes an attack meant for Hellion. Rockslide eventually reforms his body in a larger, rugged form.
World War Hulk During the "
World War Hulk" storyline, Rockslide is one of the students who battle the
Hulk when he attacks the institute. He knocks over the Hulk so the other students can hold him down, but is knocked away when Hulk regains his strength. When Rockslide attacks him alone, it appears that Hulk knows who he is and what he can do. Hulk rips off Rockslide's arms and legs, then throws them far away. His limbs are eventually located and returned to him after Hulk leaves.
Krakoan Age During the
Krakoan Age, Rockslide becomes a citizen of
Krakoa, a living island that was established as a mutant nation. During the "
X of Swords" storyline, Rockslide befriends the
Summoner, a mutant from
Arakko. However, Summoner betrays and kills Rockslide when he attempts to rescue
Unus the Untouchable. When
the Five attempt to resurrect Rockslide, they inadvertently create an amalgamation of Rockslide's alternate universe counterparts who is dubbed
Wrongslide. Rockslide is later successfully resurrected, but is trapped in the
White Hot Room before being freed. == Powers and abilities ==