If you stayed around for the ending credits for X-men: Days of Future Present, you can a scene where a powerful man makes a pyramid in the desert, while four horsemen loom in the desert. The man is Apocalypse, an X-men villain who will now make his cinematic appearance in X-Men: Apocalypse. This is what we know about X-men: Apocalypse Cast, Release Date, and Plot Rumors.
Certain cast members from past X-men films will be reprising their roles. Megastar Jennifer Lawrence will be the blue scaly Mystique, Rose Byrne will be Moira MacTaggert who was a spy in the X-men: First Class movie, Michael Fassbender will be the sympathetic villain Magneto, Evan Peters will be the Quicksilver from the X-men Cinematic Universe (not the one in the last Avengers movie), Nicholas Hoult will be the Beast (perhaps with fur), James McAvoy will be playing Charles Xavier, Lucas Till will play Havok, and Hugh Jackman will play the iconic Wolverine, for what could be the last time.
There will also be some new cast members who will play characters portrayed previously by other actors. This includes Jean Grey (Sophie Turner), Storm (Alexandra Shipp), Cyclops (Tye Sheridan), Angel (Ben Hardy), and Nightcrawler (Kodi Smit-McPhee). Then there are some new mutants added to the roster like Psylocke (Olivia Munn), Jubilee (Lana Condor), Caliban (Tomas Lemarquis), and the titular Apocalypse (Oscar Issac). A recent photo was revealed from the set that wasn't exactly flattering.
A recent article from the Latino Post showed that one of the cast members could be the one and only Taylor Swift. A recent post showed a picture of the singer next to producer Simon Kinberg, as well as actress Sophie Turner (Jean Grey) and James McAvoy (Professor X). It is possible that Swift could be doing the soundtrack, but there is an easy role that she could play, as Dazzler.
For those that aren't familiar with Dazzler, she was a pop star and a mutant who had the power to turn sound into light. Considering that X-men: Apocalypse takes place in the eighties, Dazzler would be good fit in this film. In the comics, Dazzler was created just before disco died, and she had her own comic in the early eighties that eventually focused more on her pop star career rather than being a superhero.
There has been rumors that Channing Tatum will show up in X-men: Apocalypse as Gambit, as he is slated to play the mutant in a solo film due out in 2016. Design and Trend shows that this will not be the case, as Tatum has denied it.
Speaking of Apocalypse, very little is known about the story of X-Me: Apocalypse. The official imdb page just says "the plot is unknown at this time". I have an idea that is based from the comics, and it could be the direction that they are going with.
In the Marvel Comic X-Factor, which was an X-men spinoff team with the original members (Cyclops, Jean Grey, Iceman, Beast, and Angel), there was a crossover story called The Fall of the Mutants, which had big things happen to all the mutants teams at the time, which included both the X-men and their junior team The New Mutants. It was in X-Factor #24 where Apocalypse revealed himself to New York as he had this gigantic ship the size of Manhattan itself. He then sent his four horsemen (Famine, Pestilence, War, and Death, who was Warren K. Worthington aka The Angel) to destroy New York. It was quite a story and it would be just awesome to see that put to film.
X-men: Apocalypse will be in theaters in May 27, 2016, and it should be quite an interesting development in Marvel's mutant team.