Professor X was approached by Doctor Strange to join the Illuminati. As the Illuminati fought Thanos, Strange looked into the Darkhold to find solutions in the Multiverse, destroying another universe in the process. The Illuminati found the Book of Vishanti and used it to defeat Thanos, and when Strange confessed his deeds, the Illuminati had Black Bolt secretly execute Strange.
As a result of Strange's deeds, the Illuminati were convinced that every variant of Strange was dangerous, and they quickly arrested the Doctor Strange of Earth-199999 when he and America Chavez arrived in Earth-838. The Illuminati ignored Strange's warnings of the Scarlet Witch of his reality, but they were proven wrong when the Scarlet Witch breached their headquarters while possessing the body of her Earth-838 counterpart. She promptly killed all of the Illuminati that tried to stop her; while trying to buy Christine Palmer some time to free America from her cell, Xavier entered Wanda's mind, attempting to free the innocent Wanda Maximoff of his universe from under a pile of rubble, but was quickly reached from behind by the Scarlet Witch, who ripped his head in half.
- Sir Patrick Stewart portrayed Professor Xavier in the film Doctor Strange in the Multiverse of Madness, marking the eighth and final time he portrayed Xavier on film.
- Stewart previously portrayed the Professor Xavier of Earth-10005 in the films X-Men, X2, X-Men: The Last Stand, X-Men Origins: Wolverine, The Wolverine, and X-Men: Days of Future Past, the Professor Xavier of Earth-TRN414 in the film X-Men: Days of Future Past, and the Charles Xavier of Earth-17315 in the film Logan.