FOR superhero movie fans, the $68.3 billion ($US52.4 billion) merger between studio behemoths Disney and 20th Century Fox could be Christmas come early or it could be the beginning of the end.
All your favourite superheroes are about to collide in one big movie world, even bigger than the existing Marvel Cinematic Universe (MCU).
Since 2009, when Disney bought Marvel Entertainment, the Mickey Mouse company has had the rights to a raft of your favourite comic book characters including Iron Man and Captain America.
But because of complex licensing deals, some of the most popular Marvel characters including the X-Men, the Fantastic Four and Spider-Man remained in the hands of other studios.
Disney and Sony struck a deal two years ago with Spider-Man kind of loaned back and integrated into the MCU. This saw the wallcrawler turn up in Captain America: Civil War and rebooted the franchise with Spider-Man: Homecoming, though Sony maintains the character's rights.
Now, with the mega merger, which still has to be approved by US authorities, the X-Men and the Fantastic Four could be brought back into the fold. The MCU is highly lucrative for Disney with the 17 movies released so far grossing $US13.4 billion over the last 10 years.
In a statement, Disney said the deal provides it with "the opportunity to reunite the X-Men, Fantastic Four and Deadpool with the Marvel family under one roof and create richer, more complex worlds of interrelated characters and stories that audiences have shown they love".
That means a potential team-up between Thor and Deadpool or Doctor Strange and Sue Storm. What would Magneto make of Scarlet Witch who, in the comics, is actually his daughter but whose backstory was retconned to accommodate the MCU's lack of mutant rights. Yes, you may hear the word mutant in the MCU for the first time.
Of course, you shouldn't necessarily expect Jennifer Lawrence's Mystique to share a screen with Chris Pratt's Quill, and not just because of the timeline issues.
If the X-Men are brought into the MCU, it's more than likely the current X-Men universe will be rebooted. The movie franchise has been going since 2000 and it would be far too complicated to merge two bulging universes - unless it takes a comic book route and creates some kind of infinite universe fabric of time and space rip thingumabob, which might be too much to ask a casual movie fan to grasp.
There's only one X-Men movie currently in production and that's Dark Phoenix, which is due for release in a year's time. Deadpool, which is also technically part of the X-Men universe but only tangentially connected, presents another challenge given the character and Ryan Reynolds' tenure is still new - not to mention the movie made bucketloads of money ($US783 million) and Disney loves making money. It's possible Disney may want to keep Deadpool in his own, R-rated universe.
The Fantastic Four is a much easier proposition - there has already been two reboots in the last two decades so Disney would be all too happy to blow it up and start again. Especially as the 2015 Fantastic Four was an enormous failure and one of its stars, Michael B Jordan, will feature in the MCU as another character in next year's Black Panther.
The various Marvel and X-Men TV shows will prove more of a challenge to integrate - and there are more than a dozen of them currently in production or on air - though it's possible the studio bosses will leave them as they are, also only mildly connected.
The big question is what does this all mean for the MCU's future? Marvel Studios boss Kevin Feige famously has the next 20 or so movies mapped out in his head going forward for decades.
The MCU is structured in phases (we're currently in the middle of Phase Three) and Feige has said that the fourth Avengers movies, slated for release in 2019, will be a tipping point.
He told Vanity Fair only weeks ago that everything in the MCU will be ordered as pre- or post- Avengers 4. Part of that is the contracts of its first-wave stars, including Robert Downey Jr, Scarlett Johansson and Chris Evans, will be up and Marvel has been slowly introducing its next generation of superhero stars such as Brie Larson who'll don the Captain Marvel costume.
Whether Feige has already thought about how the X-Men and Fantastic Four could feature in the MCU's Phase Four and onwards is unclear, though a potential Disney-Fox merger has been mooted for weeks.
But for those who think these superhero movie universes are already overly complicated, the injection of yet more characters into one franchise's continuity will seem like too much to take. And if it's not done right, it could be the beginning of the end of the MCU.
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