In a world where comic book movies have become a go-to genre for summer blockbuster action, it might be hard to remember that the X-Men film series was one of the first mainstream superhero movies to hit theaters - all the way back in 2000. The success of the film's sequel X2, three years later, helped maintain franchise momentum - even if the movies arrived before superheroes were synonymous with smashing box office records. That is until the one-two punch of X-Men: The Last Stand and X-Men Origins: Wolverine stalled and then undermined interest in mutant heroes on the big screen - forcing 20th Century Fox to "reboot" the series as a prequel.

With a clean slate, director Matthew Vaughn's X-Men: First Class rekindled the X-Men franchise - leading producer Bryan Singer to helm an ambitious crossover event, Days of Future Past, bridging the 2000 films with the reboot in a time-bending adventure. The ensemble picture delivered Fox's biggest X-Men payday to date - and set the stage for a new chapter, and the recasting of several fan-favorite characters, with X-Men: Apocalypse. Teased after the Days of Future Past credits, the X-Men will face their toughest enemy yet in summer 2016.

In the meantime, and on the back of the movie's first trailer, we've put together a guide to help readers prepare for Apocalypse - identifying the main characters, new and returning, that will have role in the upcoming X-Men movie. NOTE: This post contains Mild SPOILERS for X:Men: Apocalypse.

16. Apocalypse

Real Name: En Sabah Nur

Portrayed by: Oscar Isaac

While Apocalypse has long been a staple of X-Men comic books, the upcoming film adaption marks the character's first appearance in the live-action film series. Little is known, at this time, regarding how the character and his backstory might differ from comic book source material but it has been confirmed that the villain's "Four Horsemen" will play a major role in X-Men: Apocalypse.

In the comic books, Apocalypse is an ancient mutant, En Sabah Nur, that was worshipped as a god - thanks to his supernatural powers (most notably the ability to manipulate matter and energy). Over centuries, En Sabah Nur evolved into Apocalypse, experimenting with extraterrestrial technologies in an effort to increase his power. Details are still scare but early marketing materials suggest the character will see a similar origin story in X-Men: Apocalypse: when En Sabah Nur awakens from centuries of rest, only to discover that super-powered people are living in fear of humans, he vows to push mutant civilization forward - or destroy Earth trying.

15. Archangel (aka Angel)

Real Name: Warren Worthington III

Portrayed by: Ben Hardy

Another a pre-turning entry in the X-Men film roster (after an appearance in The Last Stand), it's unclear exactly where Warren Worthington III begins his journey in Apocalypse. However, in the comics Worthington's mutation manifests as a pair of feathered wings (and hollowed bones) that allow him to fly as well as support the weight of others - earning him the hero name "Angel." The character was later re-imagined for X-Factor, in which Angel's wings are destroyed during battle, crushing Worthington's spirit as a result.

Later, Worthington was approached by Apocalypse - who promised to restore the mutant's wings in exchange for service as one of the Four Horsemen. Angel agrees, and Apocalypse fashions a pair of mechanical wings as well as bestows Worthington with new powers (such as increased healing). As a result of his transformation, Angel adopts the new moniker Archangel.

14. Beast

Real Name: Hank McCoy

Portrayed by: Nicholas Hoult (previously: Kelsey Grammer)

One of Charles Xavier's most dedicated friends, and students, Hank McCoy stuck with Professor X during his darkest time in Days of Future Past. Despite the events of Days of Future Past, McCoy still hides his mutation (at least part of the time), as the film's first trailer shows both "human" McCoy and Beast.

Where exactly Singer intends to take Beast in Apocalypse remains to be seen but it appears as though the character's struggle to be "Mutant and Proud" will still be a key piece of his story - as will the ongoing turmoil that struggle creates between McCoy and his former/potential love interest Mystique. Either way, shots of a fully-furred Beast in the Apocalypse trailer confirm that viewers will also get to see McCoy take advantage of his super-human reflexes and strength (not just his genius-level intellect).

13. Cyclops

Real Name: as Scott Summers

Portrayed by: Tye Sheridan (previously: James Marsden)

Previously seen in the original X-Men trilogy, as the leader of the Professor X's adult X-Men team, Scott Summers pre-turns in X-Men: Apocalypse as a teenager, still trying to get control of his mutant powers. The energy beams that project out of Summers' eyes can be extremely destructive and difficult for the mutant to control - making them, at this stage in Summers' life, more a curse than a gift (especially for a teenage boy who, more than anything else, wants to fit in).

Scott is also brother to fellow X-Men hero, Havok. In the comic books, Cyclops was the older of the two siblings but, since Havok was already shown in X-Men: First Class (which takes place more than 15 years earlier than Apocalypse), it's safe to assume the sibling order has been flipped to maintain film continuity.

12. Jean Grey

Real Name: Jean Grey

Portrayed by: Sophie Turner (previously: Famke Janssen)

One of the most influential characters in the first three X-Men movies, not to mention X-Men comic series in general, Jean Grey also pre-turns in Apocalypse. Long before she masters her telekinetic and telepathic abilities, not to mention her potential transformation into the Dark Phoenix later on, Jean Grey in Apocalypse is crippled by visions and voices in her head.

Given the similarities between Jean Grey and Professor X's mutant abilities, Xavier makes it a point to directly oversee Grey's training - a dynamic that has regularly been featured in print (not to mention the original film series). Like the source material, the Days of Future Past epilogue suggests that Grey and Cyclops will eventually share a romantic connection in the newly established timeline; though, it's unclear whether the intervention of Apocalypse will alter that new timeline - and the pair's future relationship.

11. Havok

Real Name: Alex Summers

Portrayed by: Lucas Till

One of Charles Xavier's "First Class," Alex Summers helped defeat Magneto and Sebastian Shaw - before being drafted into the army during the Vietnam War. Bolivar Trask and Major William Stryker planned to use Havok, as well as other mutants serving in the armed forces, in development of the sentinel program but Havok is rescued by Mystique (and sent back to the states) instead.

What exactly happens between the Vietnam War and Apocalypse is not yet known; though, Havok definitely returns. Images of Alex with Scott Summers, joined by the pair's parents, confirm they are brothers (after Singer had, at the time of First Class, suggested they weren't necessarily siblings in the movie universe). The revelation shouldn't come as much of a surprise to longtime fans - given that Havok's ability to project energy is very similar to Cyclops' mutant power (who projects energy blasts from his eyes).

10. Jubilee

Real Name: Jubilation Lee

Portrayed by: Lana Condor

A longtime comic book favorite (and staple of the Fox's X-Men animated series), Jubilee finally makes a full big screen debut in Apocalypse - after three separate cameo appearances in the original film trilogy. Given that the character didn't play a role in Days of Future Past or First Class, it is unknown how Jubilee will fit into the Apocalypse storyline (aside from being one of the team's youngest, and most fashion savvy, members).

That said, the character has a long and constantly evolving place within X-Men comic book lore. While her powers have grown or been modified in various iterations of X-Men prints, Jubilee is best known for the ability to create pyrotechnic energy plasmids - "fireworks" in layman terms - that she can direct and manipulate, blinding enemies as well as exploding objects.

9. Agent Moira MacTaggert

Real Name: Moira MacTaggert

Portrayed by: Rose Byrne

Previously seen in X-Men: First Class (along with a brief cameo in The Last Stand), Moira MacTaggert was a human CIA agent - obsessed with uncovering the secrets of Sebastian Shaw's Hellfire Club. In her investigation, she enlisted the aid of Charles Xavier to help her better understand mutants - and the pair became close friends. Though, in order to protect Xavier's School for Gifted Youngsters from government control, Xavier erased MacTaggert's memory of her part in First Class and its events.

Marketing for Apocalypse suggests that, in the intervening years, MacTaggert has continued work with the CIA- investigating secret societies and other hidden threats to the world. It is MacTaggert that educates Xavier on En Sabah Nur, his Four Horsemen, and their role in the destruction of past civilizations. That said, MacTaggert isn't just an exposition machine in Apocalypse - as the trailer clearly shows the CIA agent suited up in a jump ship with the X-Men later on.

8. Magneto

Real Name: Erik Lehnsherr

Portrayed by: Michael Fassbender (previously: Ian McKellen)

Much like the comic book series, the X-Men films have attempted to walk a very fine line with "Master of Magnet," Erik Lehnsherr. In X-Men: First Class and Days of Future Past, Magneto is both hero and villain - an antagonist that resorts to evil deeds in order to protect his fellow mutants and take-down larger threats. In the first film, Magneto killed Sebastian Shaw, only to assume control of the Hellfire Club, and in Days of Future Past the mutant sought to murder Bolivar Trask on live television - to spread fear and intimidation.

As a result, it should come as little surprise that Magneto becomes one of Apocalypse's Four Horsemen. The exact reason for his willingness to aid Apocalypse in destroying humanity remains to be seen; though, Fassbender has hinted that the character is attempting to live a normal life, after falling in love, when the film opens. It's not a stretch to think that, should something happen to his lover, Magneto would stop at nothing, even aligning himself with a malevolent god, in order to get revenge.

7. Mystique

Real Name: Raven Darkhölme

Portrayed by: Jennifer Lawrence (previously: Rebecca Romijn)

In addition to Magneto and Professor X, the X-Men prequel series has centered heavily on the evolving beliefs of Raven Darkhölme - especially her understanding of mutantkind's place in the world. First Class saw Magneto help create Raven's persona "Mystique," suggesting that she should embrace her shape-shifting abilities and stop hiding her "true" self in order to fit in. By the end, with Shaw's threat eliminated, Raven sided with Magneto over Xavier. Though, Mystique soon left the Hellfire Club to pursue her own goals: liberating mutants from human control - until her blood becomes a linchpin in the sentinel program during Days of Future Past.

Charles succeeds in appealing to Raven's good nature, helping the X-Men to defeat Magneto; though, based on the trailer for Apocalypse (as well as a Days of Future Past tease revealing Raven posing as William Stryker), it doesn't appear that Mystique returned to Xavier's School for Gifted Youngsters. Instead, she continues traveling around the world, attempting to help mutants. It isn't until the threat of Apocalypse that Raven returns to the X-Men - prepared to join them in the fight.

6. Nightcrawler

Real Name: Kurt Wagner

Portrayed by: Kodi Smit-McPhee (previously: Alan Cumming)

A fan-favorite character in both print and the original film trilogy (with a scene-stealing part in X2), Nightcrawler pre-turns for X-Men: Apocalypse. As with most of the new characters, we do not know exactly how Kurt Wagner will be used in the larger film - but Singer has previously indicated that the character was rescued by Mystique and delivered to Xavier's School for Gifted Youngsters so that Nightcrawler can learn to control his teleportation abilities (and accept his physical appearance).

Nightcrawler's scenes were some of the best set pieces in X2 and Singer had repeatedly indicated an interest in bringing the character back. Time will tell how much the filmmaker draws from the comic book source material in this new version - especially given that Kurt Wagner, in the comic books, is the swashbuckling son of fellow-teleporter Azazel (featured in X:-Men: First Class) and Mystique. Given Raven and Nightcrawler's relatively similar ages in the film series, it's unlikely that Nightcrawler will be revealed to be Mystique's son in this version - though the possibility remains that Kurt could still be the lost son of Azazel.

5. Professor X

Real Name: Professor Charles Xavier

Portrayed by: James McAvoy (previously: Patrick Stewart)

Leader of the X-Men, Professor X has put aside his own self-doubt, and anger over the loss of his legs, to teach and guide the next generation of mutants - as well as face any threats that may arise. Following the events of Days of Future Past, Xavier has re-opened his school for Gifted Youngsters and resumed taking-in mutant kids in need of safe haven. Days of Future Past gave viewers a glimpse into a future where all is well with Professor X (played by Patrick Stewart) and the X-Men; however, the arrival of Apocalypse could, once again, alter that time line.

In order to save human and mutantkind alike, Professor X must rely on an untested batch of students - who will, assuming they survive the war with Apocalypse, become some of the X-Men's most powerful members. The film also marks Xavier's full transformation, teased at the end of the film's first trailer, into the X-Men's iconic leader: bald and confined to a wheelchair - but the world's most powerful telepath.

4. Psylocke

Real Name: Elizabeth Braddock

Portrayed by: Olivia Munn

One of the only Apocalypse characters that has never been featured in an X-Men movie (aside from a cameo in The Last Stand), the upcoming film marks the first major appearance by Psylocke in live-action. It hasn't been confirmed exactly how Psylocke becomes aligned with Apocalypse (as one of the villain's Four Horseman) but early details suggest the future X-Men hero may have been working for a European slave operation - led by the mutant Caliban (who was capable of sensing other mutants in hiding). Whether or not Psylocke, herself, was in need of freeing, which could explain her loyalty to Apocalypse, remains to be seen.

Either way, Psylocke has long-been a character that audiences wanted to see brought to the big screen - given that she's an important, and powerful, hero in the print source material. Originally a supporting character to her brother, Captain Britain, Psylocke eventually became a major player in X-Men books. After intense brainwashing by the Hand, and subsequent rescue by the X-Men, Psylocke became an even deadlier threat to her enemies - adding advanced martial arts and psychic-based sword skills to an already impressive resume of mutant abilities (telekinesis, telepathy, and precognition).

3. Quicksilver

Real Name: Peter Maximoff

Portrayed by: Evan Peters

After a lampooning by the internet for his silvery costume, Quicksilver proved to be one of X-Men: Days of Future Past's best new additions - thanks to a memorable slow motion kitchen fight scene. For that reason, some moviegoers may have subsequently been confused when the same hero appeared in Avengers: Age of Ultron played by a different actor (though we explained the difference between Marvel and Fox's use of the character). Regardless, Quicksilver is back for Apocalypse - with promises from Evan Peters and Bryan Singer that the speedster will have a bigger role this round.

Which, for anyone familiar with Quicksilver's comic book backstory, and parentage, shouldn't be a shock. In the source material, Quicksilver and his sister Scarlet Witch, are both mutants - and the children of Magneto. The connection is hinted at briefly in Days of Future Past but, with Magneto joining-up with Apocalypse, and Quicksilver aiding the X-Men, it's a near-sure thing that Singer will finally acknowledge and use that father-son connection to fuel the film's story.

2. William Stryker

Real Name: William Stryker

Portrayed by: Josh Helman (previously: Brian Cox)

The central villain of X2, who sought to harness mutant abilities in order to fight other mutants, William Stryker helped create the Weapon X program and, as a result, was responsible for bonding Wolverine with adamanitium. The fear-mongering mutant hater was presumed dead in the aftermath of X2; though he pre-turned in X-Men: Origins Wolverine - only to pre-pre-turn again in Days of Future Past (his father William Stryker, Sr. played a major role in First Class) as a soldier tasked with recruiting mutants for experimentation from the United States army during Vietnam.

Stryker witnesses both the danger and heroism of mutants first-hand when Magneto and Mystique confront Bolivar Trask; however, the last time viewers "see" Stryker in Days of Future Past, it is Mystique posing as the human military major (and overseeing the rescue of Wolverine). The original Stryker's actual fate remains unconfirmed - meaning that when the character reappears for X-Men: Apocalypse, moviegoers could be seeing the real Stryker or simply Mystique (still using Stryker's appearance as cover).

1. Storm

Real Name: Ororo Munroe

Portrayed by: Alexandra Shipp (previously: Halle Berry)

The last character set to pre-turn in Apocalypse, the younger version of fan-favorite heroine Storm is the final member of Apocalypse's Four Horsemen. After four appearances by adult Storm in the X-Men film series, Apocalypse will debut a less experienced version of the character - one that has yet to join-up with Professor X. As with the other Horsemen, viewers may have to wait until the film releases to discover exactly why the future hero will aid Apocalypse; yet, Singer has previously suggested that Munroe will be living from hand to mouth as an orphan on the streets of Cairo (where En Sabah Nur was worshipped centuries earlier) at the start of the film.

An orphaned Monroe, living on the streets of Cairo, is consistent with comic book lore, in which Storm was the daughter of a Kenyan princess and american photographer - until the family moved to Cairo and Munroe's parents were killed (when a fighter jet crash-landed on their house). Similarities to the source material don't stop there, as the new film will feature a very decade-faithful version of the flying, weather-controlling, mutant - with actress Alexandra Shipp even shaving part of her head to sport Storm's 1980s punk mohawk.

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Deadpool opens in theaters February 12, 2016; X-Men: Apocalypse on May 27, 2016; Gambit sometime in 2017; Wolverine 3 on March 3, 2017, and an unannounced X-Men film on July 13, 2018. The New Mutants is also in development.