ComicBook.com: In an extended question and answer session with fans, via Yahoo, X-Men: Days of Future Past writer Simon Kinberg hints at certain mutants who may be making appearances in X-Men: Apocalypse. The sometimes British, sometimes Asian, sometimes ninja Psylocke was apparently considered for inclusion in X-Men: Days of Future Past, but may yet appear in Apocalypse.
“She’s a fan favourite, and also a favourite of mine. We have a small part that she plays in ‘Last Stand’, and we talked about including her in ‘DOFP’ quite seriously actually. There was a version of the script she was in and we even auditioned some actors in Montreal. But we didn’t feel there was enough of a part she would play in a movie that was already full of many, many mutants.”
“She has a cool power. I know Bryan thinks she’s a neat character so there’s certainly a chance she’ll be in an ‘X-Men’ movie some day. Hopefully there’ll be a lot of ‘X-Men’ movies and there’s lot of mutants we’re yet to fully explore onscreen, even if they’ve had cameos before. Now we’re making more films there’s a chance to dig deeper.”