With so much attention on the X-Men's impending arrival in the Marvel Cinematic Universe, it's easy to forget that Fox isn't quite done making X-Men movies yet. On June 7, 2019, the X-Men's Jean Grey will rise as the Phoenix once again in Dark Phoenix, a film that could mark the beginning of the end for Fox's long-running X-Men film franchise. Directed by Simon Kinberg, the movie will star Sophie Turner's Jean Grey as she struggles to control the powerful force within her alongside X-movie veterans like James McAvoy's Professor X, Michael Fassbender's Magneto and Jennifer Lawrence's Mystique. Dark Phoenix will continue to chronicle the formative years of several iconic X-Men in the revised timeline that began in 2011's X-Men: First Class. Since Disney's pending Fox buyout will see the X-Men's cinematic rights transfer to Marvel Studios, Dark Phoenix will likely be the last Fox film starring a core X-Men team, and The New Mutants could bring the world that started in 2000's X-Men to a close later in 2019.

Now, CBR is taking a look at some of the things we know about Dark Phoenix, along with some wild rumors about the next X-Men movie. While there are a lot of reasons to be excited about the movie, we'll also be going through some potentially disappointing signs that we've noticed. Even though the promotional campaign for the film has really just started, we already have a lot of clues about what Dark Phoenix might have in store for Marvel's most uncanny mutants.

SPOILER WARNING: This list contains facts and speculation about Dark Phoenix, which will be released in theaters on June 7, 2019.

15 WE KNOW: DARK PHOENIX'S DO-OVER

Dark Phoenix Sophie Turner

Chris Claremont and John Byrne's universe-spanning "Dark Phoenix Saga" is widely regarded as one of the greatest stories in X-Men history, and Dark Phoenix isn’t the first time it's been adapted for the big screen. In 2006's X-Men: The Last Stand, Famke Janssen's Jean Grey also transformed into the Dark Phoenix. While the Phoenix is usually an all-powerful bird-like cosmic entity, it was essentially just a dark part of her subconscious in that movie.

While that change was heavily criticized by X-fans, Dark Phoenix seems set to be slightly more faithful to the intergalactic original saga. Jean's Phoenix powers will have some sort of cosmic connection, the X-Men will travel into space and at least one alien will pop up in the film.

14 WE KNOW: MORE FLASHBACKS

Dark Phoenix Young Jean Professor X James McAvoy

For anyone without a doctorate in mutant history, the X-Men's cinematic timeline can be more than a little confusing. The timeline was reset in 2014's X-Men: Days of Future Past and a few more times in 2018's Deadpool 2. Fox's X-movies haven't been released in sequential order either, with movies taking place from the 1960s to the near future.

Set nine years after X-Men: Apocalypse, Dark Phoenix takes place in 1992. In this timeline, Professor X, Mystique and Beast are well into training a new generation of young adult mutants that includes Cyclops, Jean Grey, Nightcrawler and Storm. As the film's first trailer revealed, the movie will also feature flashbacks to Xavier's first encounter with a young Jean in the late 1960s or early 1970s.

13 SPECULATION: JESSICA CHASTAIN'S CHARACTER

X-Men Dark Phoenix Jessica Chastain

Along with Sophie Turner's Phoenix and Michael Fassbender's Magneto, Jessica Chastain will also portray a villain in Dark Phoenix. Even though her character's name hasn't been revealed, she's been identified as an alien shapeshifter who urges Jean to embrace her newfound powers.

When Chastain's casting was announced, numerous reports identified her role as Lilandra, a longtime X-Men ally and occasional X-enemy who usually leads the intergalactic Shi'ar Empire. While Chastain has stated that she's not playing Lilandra, some rumors have suggested that her character could be a Skrull. Even though those shape-shifting aliens will appear in the Marvel Studios' Captain Marvel, the Skrulls could appear in both movies since some Skrulls are connected to the Fantastic Four's cinematic rights, which Fox currently holds.

12 SPECULATION: BASED ON ULTIMATE PHOENIX SAGA

Dark Phoenix Sophie Turner Jessica Chastain

In the early 2000s, Marvel's Ultimate Universe offered a look at a world where Marvel's biggest icons started their superhero careers in the modern age. In the Ultimate X-Men storyline "Hellfire and Brimstone," Mark Millar, Kaare Andrews and Adam Kubert offered an updated take on the Dark Phoenix Saga that could've inspired Dark Phoenix, according to some rumors.

In that storyline, the Phoenix was an entity that was worshiped by a Shi'ar religious order on Earth. Believing that the Phoenix had been reborn in Jean, these Shi'ar wanted to re-awaken the Phoenix Force to either save or destroy the world. While it's not clear who Jessica Chastain's character will be, that could be the reason that she encourages Jean to embrace her Phoenix powers in the film.

11 WE KNOW: DELAYS AND RESHOOTS

Dark Phoenix Simon Kinberg Michael Fassbender

Dark Phoenix hasn’t had the easiest path to the big screen. After 2016's X-Men: Apocalypse was only a mixed success, Fox dropped the word "X-Men" from Dark Phoenix's title and scheduled the film for release on November 2, 2018. In March, Fox pushed the film's release to February 2019, largely to accommodate the film's reshoots, before pushing it back again to June 7, 2019.

While major reshoots can indicate trouble for some productions, Fox and the film's cast have praised fire-time director Simon Kinberg and maintained that the reshoots are fairly minor. Since most of the film's cast are involved in other high-profile projects, scheduling conflicts are allegedly why it's taken the production months to complete a few weeks' worth of reshoots.

10 DISAPPOINTING SIGN: THE END OF FOX'S X-MEN

Dark Phoenix Sophie Turner Poster

Given everything we know about the timetable for Disney's Fox buyout, Dark Phoenix and The New Mutants will probably be the last Fox X-Men movies to finish production before the deal is finalized in the middle of 2019. While Fox is actively developing more potential X-Men movies like Gambit and X-Force, there's a very real chance that Dark Phoenix could be one of the last movies set in the world that started with 2000's X-Men.

Tellingly, the film's trailer prominently features a cover of the Doors "The End," with the repeated phrase "this is the end." If this is truly the end, Dark Phoenix will likely mark the end for James McAvoy, Michael Fassbender and Jennifer Lawrence's well-liked tenures as Professor X, Magneto and Mystique.

9 SPECULATION: SKRULLS INVADE

An image of Skrull warriors, one of which is mimicking Cyclops and Wolverine's looks and abilities

While the plot of Dark Phoenix still hasn't been revealed, one somewhat dubious plot synopsis hinted at several surprising plot points. This synopsis suggests that the Skrulls could use their shape-shifting abilities to infiltrate the world's governments in the film. According to this theory, Jessica Chastain's character wants to use the Phoenix as part of the Skrulls' plot to conquer Earth.

While the X-Men don't have the most extensive history with the Skrulls, they battled the aliens during Secret Invasion, a 2008 crossover where Skrulls replaced superheroes and several other prominent figures in an attempt to take over the world. Still, it would be surprising for the Skulls to take on such a big role in a classic X-Men tale that doesn't really feature them.

8 DISAPPOINTING SIGN: TOO GROUNDED

Dark Phoenix Sophie Turner Jean Grey

Since their first adventures in the 1960s, the X-Men have battled extra-terrestrial foes and taken trips into space during some of their most famous adventures. In Dark Phoenix, it looks like the X-Men will head into Earth's orbit, but it doesn't seem like they'll be heading into deep space.

If the trailer is any indication, most of the film's action takes place on Earth. While Jean transformed into the Dark Phoenix on the other side of the cosmos in comics,  the wrath of the Dark Phoenix could be largely confined to Earth in the movie. Since the original story's grand cosmic scale is a big part of what made it so special, Dark Phoenix's grounded tone could leave X-fans wanting a more intergalactic adaptation.

7 WE KNOW: GENOSHA APPEARS

Dark Phoenix Genosha

While the X-Men are off saving the world, Dark Phoenix will find Magneto trying to make a difference on a much smaller scale. In the film, he'll seemingly be in charge of establishing a mutant enclave on the small island of Genosha.

For X-Men fans, Genosha is one of the most infamous locations in the Marvel Universe. When it first appeared in Chris Claremont and Rick Leonardi's Uncanny X-Men #235, it was a corrupt country where an anti-mutant government used mind-controlled mutants as slaves. After that government was overthrown, Magneto became the island's leader and turned it into a mutant homeland. However, that effort ended in tragedy when it was totally destroyed by Sentinels in 2001's New X-Men #115, by Grant Morrison and Frank Quitely.

6 SPECULATION: MAGNETO'S ACOLYTES

Dark Phoenix Magneto Beast Storm Selene

Naturally, Magneto will have a new flock of followers in Dark Phoenix. While Nicholas Hoult's Beast and some other X-Men might find themselves siding with Magneto at some point in the film, Andrew Stehlin's Red Lotus and Kota Eberhardt's Selene will be two of his newest followers. While the super-strong Red Lotus was originally a minor X-Men ally in the 2000s, Selene is usually a psychic vampire who's one of the team's most fearsome villains.

It's unclear whether those histories could be weaved into Dark Phoenix, but their team could be called the Acolytes. After Magneto left the Brotherhood of Evil Mutants, his new followers were called the Acolytes in the 1990s, and some rumors have suggested that the Genoshans could use that name onscreen.

5 WE KNOW: NEW X-MEN COSTUMES

Dark Phoenix New X-Men Costumes

In most of the X-Men movies, the main X-Men teams have worn nearly identical superhero uniforms whenever they've gone into battle. In Dark Phoenix, they'll be keeping their group look with new yellow-and-black costumes. These striking ensembles are based on the fan-favorite uniforms designed by Frank Quitely during his and Grant Morrison's New X-Men run.

That series focused on the idea of mutants as an emergent sub-culture, and the movie seems set to explore some similar territory. While Magneto will be operating out of a potential mutant homeland, the film will reportedly start with the X-Men as trusted heroes and celebrated public figures for taking down Apocalypse in their last cinematic outing.

4 DISAPPOINTING SIGN: NO WOLVERINE

Logan Hugh Jackman

Since he clawed his way into audience's hearts in 2000's X-Men, Hugh Jackman's Wolverine has been the unquestionable star of Fox's X-Men movies. Outside of the two Deadpool movies, Jackman's Logan has appeared in every other X-Men movie, either as a main character or in a quick cameo.

Even though he had a pitch-perfect send-off in 2017's Logan, it's weird getting used to the idea that Jackman's Wolverine isn't part of a mainline X-Men movie like Dark Phoenix. While the X-movies have spent plenty of time focusing on the particulars of Wolverine's savage life, it's strange to think about an X-Men movie where his iconic hero doesn't have any presence, especially if this really is the last core X-Men movie in this continuity.

3 DISAPPOINTING SIGN: X-MEN: APOCALYPSE REDUX

X-Men Apocalypse Jennifer Lawrence

For the most part, Dark Phoenix has the same cast and team that was featured in X-Men Apocalypse. Led by James McAvoy's Professor X and Jennifer Lawrence's Mystique, the team includes Nicholas Hoult's Beast, Sophie Turner's Jean Grey, Tye Sheridan's Cyclops, Alexandra Shipp's Storm, Kodi Smit-McPhee's Nightcrawler and Evan Peters' Quicksilver.

While it's not a bad cast, that feels like an incomplete X-Men line-up. Every other X-Men movie has brought at least one new mutant into the X-Men's fold, and Dark Phoenix seems to be dropping that tradition. Since the X-franchise is about to be absorbed by the MCU, it seems like a missed opportunity to give another one of the X-Men's fan-favorite characters a moment in the spotlight.

2 SPECULATION: AN X-MAN DOESN'T SURVIVE

Dark Phoenix X-Men Grave

As the film's first trailer revealed, there will be at least one funeral in Dark Phoenix. Since Professor X, Storm, Nightcrawler and Beast were all present at the grave site, it seems safe to assume that they survive. Cyclops was also at the grave in one of the film's promo pictures. so he's probably safe too.

In terms of major X-Men, that leaves Jean Grey, Mystique, Magneto and Quicksilver on the potential chopping block. Since Jean's time as the Dark Phoenix never ends well, it wouldn't be too surprising to see her meet an untimely end. Since Beast appears to be angrily mourning in the trailer, Mystique, his on-and-off romantic interest, seems like another potential candidate for an early demise.

1 DISAPPOINTING SIGN: IT'S NOT IN THE MCU

Avengers Infinity War Concept Art

With Disney's Fox buyout set to be officially finalized sometime next year, it's only a matter of time until the X-Men and the Avengers stand side-by-side on the big screen. For a lot of fans, that moment can't come soon enough, and every X-Men movie between now and then is just delaying the inevitable.

It would probably take an impossible number of legal and contractual hurdles for Fox's Dark Phoenix to take place anywhere close to Disney's Marvel Cinematic Universe. While the jaw-dropping cosmic powers of the Phoenix and the Infinity Gauntlet could provide fairly logical ways to drop the X-Men into the MCU, audiences will have to wait a little bit longer to see all of Marvel's heroes standing together under one roof.