M is for Mystique
Along with Magneto and Professor X, Mystique's journey from frightened runaway to deadly free agent has played a major role in this trilogy of X-Men films. "X-Men: Apocalypse" will put Jennifer Lawrence's shape-shifter right in the center; we've seen in various trailers and even a scene that she's responsible for pulling together a team of X-Men to combat Apocalypse and his Horsemen. She also gives the mutants a stirring speech, proclaiming that the teenage mutants have become X-Men. Mystique spent the last two films shifting her allegiance from one side to another, but this time around she seems to be fully on board with the heroes. Whether or not we'll see Lawrence as Raven again remains unclear; her contract is up and she's not sure she'll return.
N is for Nightcrawler
Nightcrawler is another classic X-character making his way back to the big screen thanks to the franchise's all-new timeline and '80s setting. We last saw Kurt Wagner way back in 2003 when he teleported onscreen played by Alan Cumming. The character didn't return for 2006's "Last Stand" and he's been M.I.A. from the film franchise ever since. Now Nightcrawler is back, this time played by Kodi Smit-McPhee. How big of a role Nightcrawler plays in the film isn't known, but we've seen his first encounter with Mystique already and we know he rocks a Michael Jackson "Thriller" jacket too. And on top of that, he's not used to brain freezes.
O is for Ororo Munroe
After playing Storm for four films spanning from 2000's "X-Men" to 2014's "Days of Future Past," Halle Berry has passed the lightning cloud on to Alexandra Shipp, who debuts as the young Ororo in "Apocalypse." This time around, though, we're seeing a younger and edgier Storm, one that even sports the character's punk-inspired Mohawk look from the '80s "X-Men" comics. Shipp's Storm also won't be fighting alongside the X-Men, either; instead she's one of Apocalypse's Four Horsemen. But, if you're looking for spoilers, some have made it online that hint at Storm's final fate.
P is for Psylocke
Olivia Munn and Psylocke are basically inseparable at this point. Not only has Munn praised her character -- a mutant assassin with deadly mental powers -- profusely, but she's posted tons of fight training and sword swinging Instagam videos. Producer Simon Kinberg recently revealed that Psylocke was added to the movie relatively late in pre-production once they realized that they needed a fourth full-time Horseman. Munn's "Deadpool" audition and some fan art then convinced him that Psylocke would be the character to add. Psylocke's a major X-Man in the comics, and "Apocalypse" marks her true film debut following a fleeting cameo in "Last Stand."
Q is for Quicksilver
Evan Peters' speedster stole the show in "X-Men: Days of Future Past" with an audience-pleasing slow-mo scene. "Apocalypse" finds Quicksilver back in action again, this time as a full-fledged member of the team as opposed to a hired hand. "X-Men: Apocalypse" will also fully deal with a plot point that was only hinted at in "Days of Future Past": Magneto is Quicksilver's father. Besides appearing again in "Apocalypse," Quicksilver has also become a surprising spokesman for a number of products, including energy drinks, cars and internet services.
R is for Rose Byrne
After being absent from "X-Men: Days of Future Past," Rose Byrne's C.I.A. agent Moira MacTaggert returns in "X-Men: Apocalypse" to drop some needed exposition on Xavier. 21 years have passed in continuity since we last saw secret agent MacTaggert at the end of "First Class." That film ended with Charles Xavier erasing Moira's mind of recent events, including the location of his newly established school. What's happened to her character in the decades in between "First Class" and "Apocalypse" is not yet known, although it looks like she's still with the C.I.A.