A leaked teaser trailer for Avengers: Doomsday has generated significant online buzz, strongly suggesting the X-Men's integration into the Marvel Cinematic Universe (MCU). The unauthorized clip, reportedly recorded in a theater, features visuals of the Xavier School in flames and a voice-over from Patrick Stewart as Professor X. It also hints at interactions between Professor X and Magneto, and the appearance of Cyclops, marking a potential major crossover event for Marvel fans.