Although a commercial success, 2006's X-Men: The Last Stand has long been criticized for its adaptation of the classic comic book storyline "The Dark Phoenix Saga." However, co-writer Zak Penn has revealed that the original plan was to chronicle Jean Grey's transformation into Phoenix three years earlier, in X2: X-Men United.

Reflecting on his career, the Ready Player One co-writer told The Hollywood Reporter director Bryan Singer initially intended to focus on the Phoenix story in X2, but that he argued it was too soon for that development.

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"I just said ... 'You've built up this real universe and you should establish it more before you go into Phoenix,'" Penn recalled. "It was too soon to go into the Phoenix story and it was too soon to get cosmic. I would say that's probably the biggest contribution I made ... pushing it in that direction."

Penn, who shares story credit on the film with Singer and David Hayter, left X2 before it began shooting."There are a bunch of scenes I wrote that are still in there," he said. "I don't remember what movie I left to do while they were making X-Men 2, but that was kind of the story of my life. I would come in and do something and then leave."

He returned to write The Last Stand with Simon Kinberg, who'll take another stab at "The Dark Phoenix Saga" in 2019 with X-Men: Dark Phoenix. The film was originally scheduled for release on Nov. 2, 2018, was pushed back this week, reportedly to accommodate reshoots.

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