Shi'ar Empress Lilandra and the Hellfire Club were important parts of Chris Claremont and John Byrne's "Dark Phoenix Saga." However, they won't be a part of the upcoming Dark Phoenix film. Director Simon Kinberg has now explained why.

"I think if I had four hours to tell this story I would've included the Hellfire Club, I might've included Lilandra," Kinberg told Digital Spy.

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The director then explained he wants "to go a little more vertical" with his characters in Dark Phoenix and flesh them out more, especially Jean Grey.

"So while I loved the Hellfire characters and their role in the Dark Phoenix saga in the comics," he continued, "and I loved the Lilandra storyline in the comics, all of those felt like they were going to start to compete with the main story of Jean and her emotional crack-up and the break-up of the X-Men family."

In the comics, the Hellfire Club plays a key role in the comics, as members Mastermind and Emma Frost manipulate the Phoenix into taking on the identity of the Black Queen. This eventually leads to a confrontation between the X-Men and Lilandra as well as her Shi'ar Imperial Guard.

Dark Phoenix is one of the final films in Fox's mainline X-Men franchise, which launched in 2000. Disney has reacquired the rights to the Marvel characters once held by the studio. However, Marvel Studios President Kevin Feige says fans shouldn't expect to see the mutant team in the Marvel Cinematic Universe for "a very long time."

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Directed and written by Simon Kinberg, Dark Phoenix stars James McAvoy, Michael Fassbender, Jennifer Lawrence, Nicholas Hoult, Sophie Turner, Tye Sheridan, Alexandra Shipp, Kodi Smit-McPhee, Evan Peters and Jessica Chastain. The film arrives June 7.