Like Sony Pictures and their planned spin-offs featuring The Sinister Six and Venom, 20th Century Fox are putting plans in place to expand the X-Men and Fantastic Four's cinematic universes. According to X-Men: Days of Future Past producer Lauren Shuler Donner, "There was a regime [at the studio] that didn’t see the worth in [spin-offs], and the current people who run Fox understand, embrace it, and we’re going to do right by it. I’d like to do Gambit. I’d like to do Deadpool. We’ll see. There’s a lot of really great characters." All names we've heard before, but producer and writer Simon Kinberg - the man apparently tasked with creating Fox's larger Marvel Universe - had this to say about another possible spin-off. "I love what Jen Lawrence has done with her, and I feel like because she is in such a crowded ensemble, there’s so much more opportunity if you were to follow her solo." Would you guys like to see Jennifer Lawrence's Mystique get her own movie? Be sure to sound off with your thoughts on this news below!
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Why haven't they done it sooner.

Makes sense. She's turned into one of the biggest actresses out there, and she's probably under contract to them, so why not capitalise on her fame?

I can't seem to figure out how Havok fit into the first class scene timeline wise, isnt he Cyclops half-brother or some hoohah? But agreed with Mink, they own her in the sense of contract and whatnot... it works.

S.Q.U.A.S.H wrote:

I can't seem to figure out how Havok fit into the first class scene timeline wise, isnt he Cyclops half-brother or some hoohah?  But agreed with Mink, they own her in the sense of contract and whatnot... it works.

Because they screwed up the timeline completely. In First Class, Emma Stone is an adult. In Origins: Wolverine, she's one of the kids that Wolverine saves. However, in Origins: Wolverine, Professor X is an adult, and in First Class we know he's young.

They'll probably ignore that Havok is Cyclops' younger brother, as to them it's probably a minor detail.