Mister Sinister

Few villains in the Marvel Universe have cast as long a shadow as Mister Sinister, who slithered onto the scene in 1987 — courtesy of creators Tom DeFalco and Rick Leonardi — and has been unsettling readers ever since. Emerging at the dawn of the Copper Age, this obsessive, calculating presence has proven remarkably durable, accumulating nearly four decades of appearances and earning a place among Marvel's most enduring antagonists. He's kept the most distinguished company imaginable, sharing pages with the likes of Wolverine, Cyclops, Storm, and Scott Summers across landmark runs including Immortal X-Men, Reign of X, and Trials of X. Perhaps most intriguingly, the facts list him among the X-Men's own roster — a complicated, collector-worthy detail that speaks to just how deeply Sinister has woven himself into the fabric of mutantkind's ever-shifting saga.