Leaked details for Marvel's upcoming 'Avengers: Doomsday' suggest the potential return of X-Men characters Professor X, Magneto, and Cyclops. Rumors describe scenes of Professor X and Magneto playing chess, highlighting their complex rivalry, and Cyclops in battle. While Marvel Studios has not confirmed these leaks, fans are excited by the prospect of legacy actors reprising their roles, aligning with the franchise's multiverse and legacy character focus.