Charles Xavier

Strange takes America to Earth-838, where he meets the Illuminati: Mordo, Peggy Carter as Captain Carter, Blackagar Boltagon (Black Bolt), Maria Rambeau as Captain Marvel, Reed Richards (John Krasinski), and Professor Charles Xavier — Patrick Stewart, in the animated-series wheelchair. Wanda kills all of them.

Charles Xavier runs a school that shelters and trains them and advocates coexistence. The film establishes the shape of everything that follows: Xavier and Magneto as friends who agree entirely about the danger and completely about nothing else, and Wolverine as the outsider who has no memory of his own past and therefore no stake in either argument until he chooses one.

X2: X-Men United (2003) — Colonel William Stryker, the man who put the adamantium on Wolverine, attacks the school and attempts to use a captive Xavier to kill every mutant alive. Stryker runs a black-site programme on mutants and has a personal stake: his own son is a mutant, and he blames Xavier for it. His weapon is Cerebro — Xavier's telepathic amplifier, which can locate every mutant on Earth and, if the operator wills it, kill them all at once.

Jean returns as the Phoenix, kills Cyclops and Xavier, and is stopped by Wolverine.

In 1973 he has to reunite a Charles who has given up — drugging away his telepathy to be able to walk — with a Magneto imprisoned under the Pentagon for the Kennedy assassination. Charles stops her not by force but by asking, on live television, and she chooses to walk away.

Xavier has a degenerative brain condition that causes lethal psychic seizures. Xavier, in his nineties, has a degenerative brain condition that turns the most powerful mind on Earth into a weapon of mass destruction during seizures — the film quietly establishes that one such seizure already killed most of the X-Men.