WhileMatthew Vaughnmade one of the best superhero movies in recent memory with the reboot/prequelX-Men: First Class, his time in theX-Menfranchise was not supposed to be a one-and-done. After the whirlwind experience of makingFirst Class, Vaughn was signed on to co-write and direct the sequel, which would move the time period to the 1970s and bring the Sentinels into the mix. But deep in development, Vaughn exited the project,Bryan Singertook over, and it became theX-Men: Days of Future Pastwe know today.
However, Vaughn recently revealed that hisoriginalplan for theFirst Classsequel was to introduce a new young Wolverine character, with theDays of Future Paststoryline not coming into play until the third film. Speaking withUproxx, Vaughn shed some light on his early plans for theFirst Classfollow-up:

“The reason I haven’t done sequels in the past is they just weren’t exciting me. And onDays of Future Past, even though I co-wrote the bloody thing, the reason I bailed out of it is two things: First, I respect Bryan Singer hugely and X-Men is Bryan’s world and I feel he let me play in his sandbox. I enjoyed it, but it wasn’t my sandbox. I wanted my own sandbox. And, second, I didn’t want to doDays of Future Pastnext. I felt that one should be in a trilogy andDays of Future Pastshould be the finale of that story. I would have done a film in-between where you meet the young Wolverine and a new character, and thenDays of Future Pastbecame the young Wolverine and the old Wolverine and just really blow it out.”
Vaughn goes on to say that the studio didn’t agree with this plan and wanted to makeX-Men: Days of Future Pastnext, which is one of the reasons he left to go makeKingsman: The Secret Service.

Curiously,Vaughn spoke with us in 2014about his originalDays of Future Pastplans and said the finished film was “90%” of what he had written before he left the project:
“Bryan [Singer] did a few things, which I thought were genius that weren’t in my script. I had Juggernaut breaking into the Pentagon, he changed it to Quicksilver and did that fucking brilliantly, I have to add. My idea was the sentinels at the end, I wanted them to look like Mystique. I thought there should be thousands of Mystiques attacking them in the future. He changed a few more of the mutants, but it was pretty close. Yeah, it was pretty close.”

So when Vaughn says he wanted to do an in-between movie beforeDays of Future Past, it sounds like that idea was shot down early in the process and he moved on to co-writing and developing to direct theDays of Future Paststoryline. But as Vaughn says, his heart wasn’t really in makingDays of Future Pastnext, and that was one of the factors that contributed to his exit.
Vaughn was also attached to directX-Men: The Last Standin the mid-2000s, but left the project pretty far into pre-production, at which pointBrett Ratnertook over. Vaughn instead went and madeKick-Ass, a subversive take on the superhero movie, and indeed the filmmaker has been charting his own course ever since. So if hedoesend up makingMan of Steel 2we know two things will be true: His heart is 100% in it, and the movie will be somewhat insane.
