In the 26 years since the X-Men starred in their first big-screen adventure, plenty of ink has been spilled (by yours truly, especially) on their iconic introduction. X-Men began with the origins of its villain, Magneto, who tapped into his inimitable powers on the darkest day of his life. In 1940s Poland, the character — then known just as Erik Lensherr — bent the gates of a concentration camp into the shape of an X. It was the perfect overture not just for mutantkind, whose plight has always run parallel to real-world tragedies, but for Magneto’s relationship to power and...