Who he is: Professor X, a.k.a. Charles Xavier
His power: Professor X is an extremely powerful telepath who can read and control minds, create psychic illusions, form mental barriers to block out memories, and freeze entire rooms of people in their tracks. He can also transfer his consciousness into other bodies.
His story: Raised in wealth, Charles has an easy childhood with his best friend, Raven, and he becomes an ally of the CIA as an adult when they need an expert on genetic mutation. Working with Erik Lehnsherr, Charles assembles a team of young mutants for the CIA, and they take down Sebastian Shaw’s Hellfire Club in X-Men: First Class. Magneto accidentally paralyzes Charles from the waist down at the end of that film. In the decade that follows, he becomes addicted to a serum that restores his ability to walk but negates his mutant powers, the U.S. government adopts a harder stance on mutants, and the Vietnam War takes a toll on the new Xavier’s School For Gifted Youngsters.
In the original X-Men Universe timeline, Charles regains the ability to walk while retaining his telepathy based on his appearance in X-Men Origins: Wolverine. The events of X-Men occur decades later and show Charles comfortably in charge of a flourishing Xavier’s School. He continues to have a complicated relationship with Magneto, and whenever Erik tries to make humanity pay for the mistreatment of mutants, Charles and his X-Men are there to stop him. In X2, Charles is kidnapped by Maj. William Stryker and psychically deceived into almost killing the mutant race, but he’s saved at the last minute and gives the president a stern warning at the end of the movie. Charles is seemingly killed by the Phoenix in X-Men: The Last Stand, but he transfers his consciousness to a new body that allows him to continue leading the X-Men.
The Charles Xavier of 2023 sends Wolverine back in time to prevent a dystopian future in X-Men: Days Of Future Past, which creates the new XMU timeline. In this new continuity, Charles helps Wolverine free Magneto from prison and kicks his drug habit to stop Magneto and Mystique from making decisions that would threaten the future of mutantkind. Charles finally shaves his head in X-Men: Apocalypse and is kidnapped once again by a villain who wants to use his powers to accomplish a villainous plot, but instead of killing mutants, Apocalypse wants to take over Charles’ mind and body and use his psychic abilities to destroy and rebuild the world. The X-Men save Professor X before Apocalypse can complete the transference ritual, and the movie ends with Charles training his new class of students.
Xavier reappears in Logan, now infirm and prone to seizures. (It’s heavily implied that he killed several students and X-Men in Westchester after losing control of his powers during one such incident.) Burdened with guilt and suffering from dementia, and with his brain now classified as a weapon of mass destruction, his urge to help others is rekindled by the presence of the young clone Laura. Despite frequent bouts of recrimination, Xavier ultimately acknowledges that his surrogate son is doing his best to stop him from killing or hurting anyone else; shortly after, he’s murdered by X-24, Logan’s murderous clone. Mourning his friend and mentor, Wolverine buries his body in a quiet forest glade.
Played by: Laurence Belcher (young) in X-Men: First Class; James McAvoy (adult) in X-Men: First Class, X-Men: Days Of Future Past, and X-Men: Apocalypse; and Patrick Stewart (older adult) in X-Men, X2, X-Men: The Last Stand, X-Men Origins: Wolverine, The Wolverine, X-Men: Days Of Future Past, and Logan
Currently, Professor X is: Both dead (in 2029) and back at the X-Mansion, helping young mutants realize their full potential in other eras.
Where will we see him next? Patrick Stewart is done with the part—and James McAvoy’s contract is currently up—but that’s not going to stop someone from playing Professor X the next time an X-sequel comes around.