Mountjoy
Mountjoy is a mutant villain from the X-Men corner of the Marvel Universe whose ability to physically merge with and inhabit other people's bodies made him a dangerous threat to Bishop and his allies in the early 1990s X-universe.
Few villains earn a series subtitle quite like Mountjoy did β Bishop: The Mountjoy Crisis makes this Marvel antagonist's importance to the X-universe unmistakably clear. Debuting in 1994's Bishop #1, crafted by John Ostrander and Carlos Pacheco, Mountjoy emerged at the height of the Copper/Modern Age as a genuine threat worthy of sharing pages with Lucas Bishop, Shard, and even Charles Xavier himself. Though the catalog appearances are select rather than sprawling, the fact that Marvel saw fit to revisit this material in reprint speaks to the character's staying power within Bishop's corner of the X-Men mythos. For collectors who love a villain with real gravitational pull on the heroes around them, Mountjoy is a name well worth tracking down.
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