The true indicator of how much of a threat the Sentinels were was in Chris Claremont and John Byrne’s iconic two-part storyline, “Days of Future Past.” Running in 1981’s Uncanny X-Men #141 ...

In the future, the mutants and the humans who help them are slaughtered by powerful robots named Sentinels. Professor Xavier, Wolverine, Magneto, Storm, Kitty Pryde, and her friends meet at a ...