When Julio was a teenager and his mutant powers had manifested, he was kidnapped by the anti-mutant group, The Right. He was held captive and his powers were exploited; he was made to create "earhtquakes" that toppled towns. X-factor finally came and rescued Julio in X-factor #17. Julio went with X-factor back to New York and stayed with them. Later it was discovered that the leader of The Right was none other than Cameron Hodge, PR guy for X-factor.
While with X-factor, Julio and other mutants that X-factor helped formed a group within X-factor called the X-Terminators. The group was composed of Boomer, Rusty, Skids, Artie, and Leech. The X-Terminators later joined with the New Mutants, but without Artie and Leech. Julio did not remain with the New Mutants for very long.There was this whole Rahne romance thing going on with him and he ran off to Genosha right before Calbe changed the team into X-Force. Sometime after (at least so I assume) he learned of his father's death. He went to Mexico to find out what happened, and learned that the man who killed his father was New Mutant leader, Cable.
After Julio learned this, he went on a hunt; he attempted to track down Cable and kill him. He met up with G.W. Bridge and Weapon: Prime who also wanted Cable. They went after him and a battle insued between them and X-Force, which Cable had formed from the ashes of New Mutants. Julio learned after the battle that it wasn't Cable that had murdered his father, but Cable's clone, Stryfe. Julio ended up joining X-Force.
Since joining X-Force, Julio and fellow teamate, Shatterstar, have become close friends; although in the begining Julio couldn't stand Shatterstar. They remain close friends today, even though Ric keeps leaving the team. Rictor did come back to help Shatterstar when all that weird Shatterstar/Benjamin Russel stuff went down (that I to this day fail to understand). After the whole Zero Tolerance mess Cable asks the team to assume false identities and lay low (issue #70) the team says no way, and Rictor and Shatterstar head off to Mexico because Rictor wants to get his family out of gun dealing. We see them briefly again, when Arcade tricks Rictor in Mexico and traps him in order to force Shatterstar to fight Domino.
That's when we last saw Rictor and Shatterstar, but hopefully they'll pop up again soon.