Timeline A: 2023, Timeline B: 1973
A decade later, that future has come to pass: declining relationships between humanity and mutantkind see the resurgence of the assassinated Bolivar Trask’s Sentinel program. Sentinels go on to wipe out the vast majority of mutantkind, but not before a remaining handful of X-Men, alongside Charles and Magneto, use Kitty Pryde’s powers as a mutant circuit to send Logan’s consciousness back in time to his body in 1973, to try and convince Charles and Erik’s past selves to stop Mystique from assassinating Trask. Logan eventually succeeds, and Raven is convinced to not kill Trask, joining Charles as a senior leader in the X-Men.
Erik, who decided to try and get Raven to kill Richard Nixon instead, goes his separate way once more after Raven saves the president—and after the public sees a mutant saving the day, Nixon is convinced to not put the Sentinel program into effect. Timeline A Logan’s mind returns to his own continuity, learning that Raven’s act erased the original dark 2023 of Timeline A and replaced it with one where the X-Men and many fallen mutants are still alive. (X-Men: Days of Future Past).
