Belasco will be the villainI admit I can't think of how exactly they'll do him, but there're only so many villains they have left to use. Magik is confirmed and Limbo would sort of fit the idea of it being a "teen horror movie". Perhaps he'll be another mutant in the vein of Nightcrawler or Azazel, but immortal (using Apocalypse's technology, perhaps?).
- The Demon Bear from Dani's dreams is alleged to be in the film. Perhaps it'll be one of Belasco's many forms, making him an Expy for Freddy, the quintessential monster from teen horror films
- The Demon Bear is already a shapeshifter itself. And what would make for a better face reveal in a horror movie? A redheaded guy in a tunic or a gigantic bear with claws bigger than a person?
- They could possibly save him for a sequel, and foreshadow his existence in the first New Mutants film.
- Word of God is that the film is based on The Demon Bear Saga, which lends credence to the Demon Bear being the villain instead.
- It could be a "Belasco uses different illusory forms for each of the kids, and the bear is just what he uses for Dani" thing, but from the perspective of the guys handling press release info, there's really no reason they'd hide Belasco's role, since he's not exactly popular enough that suddenly revealing him in the movie would be a meaningful twist to anyone.
- Exactly, why would they use that story as a base but change the Demon Bear into another villain who already has similar powers?
- Wouldn't be the first time they've used a character as a base only to pull the rug out from under us note
- They have tons of villains aside from Belasco to use. And having it be that focused on Magik alone would be detrimental to establishing the whole team.
- ALL Jossed. Belasco does not even appear in this movie.
Warlock will appear as a prototype future Sentinel created from experiments done on the New MutantsThe plot's said to feature the team "escaping from a secret facility". This seems as good an explanation as any for what was happening at that facility. However, he'll be revealed as a good guy in the end- maybe Fox's answer to the Vision?
- In another quiet agreement with Marvel Studios, Fox will be careful to always call him Warlock, and the Guardians of the Galaxy will only ever call their similarly named character Adam.
The story will be set in the same time period as LoganPresuming, of course, that Fox is even worried about continuity at this point.
- Jossed. Word of God places it roughly contemporary with Deadpool (2016).
- Jossed again, as Word of Disney (which is basically Word of God) has stated it is now part of the Marvel Cinematic Universe. 
The film will make direct connections to the rest of the X-Men Cinematic UniverseThe film is indicated to be set at roughly the same time frame as Deadpool (2016), which means we're going to see the following connections trying it into the present day setting of the X-Men Film Universe:
- Illyana, being Colossus' sister, is one all on its own. At some point she'll mention an older brother she's not seen for a while.
- The installation where the kids are being kept is somehow connected to the Workshop where Wade was experimented on. It may also be implied that Transigen or Essex Corp. is involved.
- In fact, the events of this film will be why Transigen relocates to Mexico.
- Confirmed, and it even has uses archive footage from Logan.
- A post-credits scene will set up Deadpool II or X-Force, possibly including a cameo by Colossus looking for Illyana.
- One or more of the X-Men will appear to collect the kids and bring them to the school once they escape.
- Cecilia Reyes will be revealed to be Laura's mother.
- Cannonball will be implied to be a member of Cable's team in the future.
- The Demon Bear will say "I have plagued humanity before mutants even began to be born, long before the time of En Sabah Nur, and even longer before the Phoenix Force set the Shi'ar on their quest to exterminate it from the cosmos!"
Connections to the other X-Men films will be kept very subtleAlternately, as New Mutants is a significant Out-of-Genre Experience, it won't be littered with overt links to the other films. Magik being the sister of Colossus will be the one that is directly referenced, but it won't feature an appearance by a full team of X-Men, and won't directly state that the hospital/facility is linked to any of the others aside from very vague hints at having "higher ups" above Dr. Reyes.And the fanboy rage that results from a fan favorite being killed off would be fun to watch!
- Perhaps it'll be Cecilia Reyes instead of any of the mutants.
- Confirmed, you guessed it two years ago.
- Not Jossed per say, but Josh Boone has said New Mutants is intended to be a trilogy. Therefore it's highly unlikely that any of the team will be killed offnote .
- Maybe they'll only kill off one of the kids, though?
They will somehow address Sunspot's Race LiftMaybe in this version, he's of mixed descent and one of his parents are Afro-Brazilian. That still provides some of the drama from his backstory. Doesn't fix the whole thing but it's at least something.
- Perhaps his drama can stem from realizing he's not his parents' biological child.
The man in the paper mask from the trailer is actually WarlockHe doesn't have the ability to look totally human, so he covers himself up when he isn't using his powers.
- Jossed, it's the Smiley Men.
- Alternatively to the theory under XCU connections above, it will be revealed that Cecilia is Sunspot's mother. The actors are both Brazilian after all.
- She'll have no connection to any of the New Mutants, X-Men, or X-23 kids, aside from being a fellow mutant. I mean, let's face it; if Rosario Dawson had been able to stay in the role as originally planned, no one would be assuming that she must be related to the other Latin American characters like Laura. If it was considered to have her character be that closely related to Laura or Sunspot, then Dawson would of never been set for the part in the first place (unless they tried to pull some really unconvincing Fake Mixed Race). I tried bringing these points up above, but it always got deleted, even if I resorted to just pointing out that the time scale doesn't add up and ignoring race and nationality altogether!
- Reyes will be a Decomposite Character, with her name and status of a doctor going to the doctor running the facility keeping our heroes locked up and her heroic attributes being given to another character, possibly her younger relative.
- The threatening, callous Dr. Reyes is actually the Demon Bear taking her form to manipulate the New Mutants. The real Reyes is either another prisoner of the facility or a former employee who doesn't suspect that her identity has been stolen by another "person".
The Demon Bear will be referred to as a mummudraiLike Cassandra Nova, it appears to be going the "supernatural psychic astral entity" route. Maybe the term will be introduced as a word for evil spirit in certain local (fictional) indigenous peoples.
All the supernatural poltergeist stuff from the trailer will turn out to be harmlessThe frightening imagery is not in of itself a threat to the kids.
- It will all be revealed in the film to be a result of Dani's powers to manifest the fears of those she targets running out of control. This will serve as a Red Herring that will make the others doubt the existence of the Demon Bear.
- Alternately, it'll turn out to be some kind of psychic message trying to warn the New Mutants about the real threat probably a member of the facility staff who's insane or otherwise evil.
The facility is operated by the US government, possibly as an extension of Project X.
The troubled backstories of our characters will be seen as nightmares they have at nightThis is how the Demon Bear will become powerful enough to threaten them despite it being vulnerable to their powers. Just like in the comics, it will draw power from negative emotions.
The reshoots are being used to make the film slightly more similar to the other X-Men moviesMaybe to strengthen its connection to the rest of the brand. It'll still be mostly a horror movie, but with a few more overt nods to the rest of the universe it's in.
The absence of Karma is intentional.However, it's not because of the Unfortunate Implications (because she's Vietnamese and a lesbian) but because her role is too spoiler-heavy to put in the trailers. Y'know, just like Hawkeye!
If the above theory is true, then Karma will be played by:
- Bex Taylor-Klaus
- Bofo Fremkser
- But none of these people are Vietnamese...
- While it's long been jossed that she's going to be a part of the movie, I personally see her being played by Lana Condor if she ever appears in the MCU — if only because she's the only actress of Vietnamese descent that could believably play someone around Karma's age that I could find (and disregarding the fact that she already played Jubilee in previous films).
If rumors are to be believed, this will be the first MCU-Fox movie.Personally, I could see this happening. If the MCU is going to start out with the X-Men, it would be best for them to start small. There is also talk about the film being set in the 90s. In current day, mutants live in hiding to prevent the events of New Mutants happening again. After Thanos' snap in Avengers: Infinity War, the Mutants will no longer live in hiding and defend the Earth.
- Well, Roberto is apparently among the victims of the Decimation according to the San Fransisco memorials in Endgame.
- JOSSED hard.
The New Mutants will be connected to Runaways (2017)If the rumours of the movie being moved to Hulu are true. Maybe the Staff of One will appear somewhere in the hospital in one scene?Alternatively...
The New Mutants will be connected to the Marvel Netflix showsThere are rumours of Hulu picking up all of the cancelled Netflix shows. This could also work with the Darker and Edgier tones of the shows, making the New Mutants feel right at home!
This movie will subvert the Comic-Book Movies Don't Use Codenames ruleThere will be a scene similar to a scene in X-Men: First Class where the kids are together and they come up with names for their superhero personas.
- Jossed. In fact, the movie does not have superhero names outside of the Magik joke.
Sunspots new origin was (minimally) inspired by Ultimate X-Men #41 (New Mutants: Part 2)Going about his day, meeting with his girlfriend, and eventually (accidentally) frying her to a crisp
Stan Lee will make a posthumous cameoSince they are using the orignal cut, Stan Lee might have a chance of appearing in the movie.
"Cry Little Sister" will play over the credits
- Jossed. It's nowhere to be found in the movie.
Demon Bear has possessed Cecelia Reyes
Reverend Craig Sinclair will appearRahne's abusive fundumentalist father could appear as a manifestion of the Demon Bear.
This is just a huge cover-up for Deadpool 3
- JOSSED hard.
This film will go to VOD on Comic Con@HomeJossed.
This film will become a midnight Cult Classic of the 2020s.
- Just like Scott Pilgrim vs. The World.
The Smiley Men represent the 18 men Illyana killed.
- As a child, Illyana was taken as a Sex Slave and was tormented by the Smiley Men. Prior to her arrival at the hospital, presumably, while she was still a sex slave, Illyana also killed eighteen men one by one. But what if the Smiley Men, in reality, were the men who...used her, as seen with a child's eyes?