Codename: Colossus
Real name: Piotr Nikolaievitch Rasputin
Relatives: Nikolai (father, deceased), Alexandra (mother, deceased), Mikhail (brother), Illyana (Magik, sister, deceased), Peter, Jr. (son)
Past: Colossus can transmute his entire body into solid organic steel. His strength greatly increases upon transformation, as does his height and mass. In armored form he is nearly invulnerable, and doesn't need to breathe or eat. Piotr is an accomplished artist, but too often finds that his world is shattered by violence and death. During the Mutant Massacre he was seriously injured by Riptide, whom he then killed. Only Magneto's metal and energy-manipulating powers were able to save him. However, Peter was trapped in his armored form for a long time. He has lost his entire family, and for a time (due to a head wound received from the X-Cutioner and the tragic death of his sister Illyana) gave up Xavier's dream and joined the Acolytes. However, he returned to the fold shortly thereafter, and went to visit his good friend Nightcrawler  and his old flame Shadowcat, then members of Excalibur. He found Kitty kissing her then-boyfriend Wisdom and flipped out, beat Pete nearly to death. Pete managed to hotknife Colossus in the spine, and the team took him in as part of his "rehab." He came to accept his role in Excalibur and remained there until the team's dissolution, whereupon he returned with Kitty and Kurt to the States to rejoin the X-Men. Peter once again was a mainstay of the team, though the loss of his sister continued to haunt him. When Professor X seemed to be pushing the X-Men too hard after their return from the Skrull homeworld, Peter left with Marrow on a trip to some museums, where they encountered Mikhail, who was trying to bring Illyana back to life. As much as it hurt him, Peter had to stop Mikhail, but in the process managed to return him to our dimension and separate him from an energy parasite that was inhabiting him and driving him crazy. Unfortunately, Peter lost his brother again when Mikhail used his power to remove himself and Apocalypse's Horsemen from our reality. Still, Peter seemed at peace. Unfortunately, his peace was not to last. After the tragic death of Moira MacTaggert, Beast was finally able to synthesize the cure for the Legacy Virus, based on Moira's final thoughts and notes. He revealed his findings to his teammates, and Peter felt profound relief. Upon further analysis, however, they discovered that the only way to release the cure would kill the person into whom the cure serum wa injected. After the others left the lab, Peter stayed behind. Cecilia Reyes seemed to sense what he was planning, but Peter sprayed her with knockout gas before she could stop him. He took the cure and injected it into himself, releasing the cure and saving thousands as he himself died.