AVENGERS ASSEMBLE! Mutants have officially entered the endgame! Marvel just confirmed the long-awaited #XMen debut in #AvengersDoomsday in a new trailer! Patrick Stewart's 'Professor Charles Xavier,' Ian McKellen's 'Erik Lehnsherr/Magneto,' and James Marsden's 'Scott Summers/Cyclops' headline, offering our first look at the stars reprising their superhero roles from the previous 20th Century Fox era of X-Men movies, now in the Disney-owned Marvel Cinematic Universe. It’s a game-changing moment f