In recent years, the casts of superhero films have expanded to include more costumed characters than ever before. Big films like "X-Men: Days of Future Past," "Batman v Superman: Dawn of Justice" and "Captain America: Civil War" have featured dozens and dozens of characters between them.

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Marvel's "Guardians of the Galaxy" franchise already has a head start when it comes to big casts, since the film series stars a team as opposed to a solo hero. The sequel, which rockets into theaters this May, sees the titular team's roster expand from five members (Star-Lord, Gamora, Drax, Rocket and Groot) to eight with the addition of Nebula, Yondu and Mantis. As if that wasn't enough, writer/director James Gunn revealed to ComicBook.com during their set visit last year that the sequel's initial treatment included another major character.

"I'll say one major thing that happened during the treatment phase, not even during the script phase," said Gunn. "During the treatment phase, there was another character that was a major character, that was a part of the treatment. Although it kind of worked generally in the story, I got to the place where there were too many characters. I think 'Civil' War handles a lot of characters really well, but they're minor characters, and in this movie, every character has their own arc, their own thing. And I thought it was one character too many, so I took one of the characters out of the story about half way through the treatment phase."

Gunn didn't identify who the character was, but there are plenty of unused cosmic characters in Marvel's library to choose from. The decision to remove the mystery character proved permanent, as Gunn revealed that the initial treatment is pretty much what the finished film turned out to be. "[T]he eventual 70-page treatment, which is what it was, is what this movie is, and it has changed very, very little. And there's been almost no changes in the past three or four months before shooting; minor, minor lines here and there. We did rehearsals and some things I changed because of that. Now, who knows, we may get into post and go 'oh my God, let's change everything,' I hope that isn't the case, but I've been really fortunate."

Written and directed by James Gunn, “Guardians of the Galaxy Vol. 2″ stars Chris Pratt, Zoe Saldana, Bradley Cooper, Dave Bautista, Vin Diesel, Karen Gillan, Pom Klementieff, and franchise newcomer, Kurt Russell, who plays Star-Lord’s father – Ego, the Living Planet. “Guardians of the Galaxy Vol. 2” arrives in theaters May 5.