When taking the time to launch a new franchise, it's hard to fully flesh out all of the characters involved. This was the case with 2014's "Guardians of the Galaxy," which not only introduced the core Guardians team, but also Gamora's sister Nebula and Star-Lord's father-figure Yondu. While the Guardians had a small following ahead of the film's release, these characters were considered D-listers. Following the first film's massive success, though, the Guardians became Marvel Cinematic Universe mainstays. For those looking to get to know the rest of the Guardians -- namely, Gamora, Nebula, and Rocket -- it appears you'll have to wait for "Guardians of the Galaxy Vol. 2."

As Gillan explained to Screen Rant, we'll learn more about Nebula and Gamora this time around. "We learn a lot about their backstory actually and what happened to these two girls growing up," she revealed. By explaining their backstories and how Thanos impacted their lives, we'll come to learn just why the relationship between the two sisters is so fractured. However, there will not be flashbacks of any kind. Instead, the backstories will merely be addressed in conversation.

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Gillan's on-screen sister Zoe Saldana (Gamora) also addressed the relationship between the two characters and how James Gunn went about further developing their stories for "Guardians of the Galaxy: Vol. 2." Saldana was thrilled with what Gunn managed to accomplish with the two sisters this time around, stating that she feels he did open a new window in this installment. "When it comes to her relationship with Nebula, I appreciate what James Gunn did," she shared. "He definitely heard what the fans were saying, you know."

While Thanos may not be in this film, it sounds as though it's safe to say his presence will be felt. When asked why Gunn decided to not bring Thanos back for this film, the director explained that the story being told here is one about two sisters: "It’s not about the sisters and their father. It’s about two sisters and what were the sisters’ problems with each other."

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Of course, the lack of Thanos isn't the only change we can expect from "Vol. 2." For Gunn, it was also important that he take the secondary characters and make them "major characters" for the sequel. Fans can expect to learn more about not only Gamora and Nebula, but also Michael Rooker's Yondu. Instead of using this film to tell more of Star-Lord's story, Gunn decided to make it the whole team's story. This was a decision that came about while he was at work on the first film. "When I was writing up the first movie I wrote the whole backstory of where Peter came from, who his father was, why did Yondu pick him up from the planet," he said. "I wrote all that stuff, and there was a part of me that thought about 'Guardians of the Galaxy Vol. 2,' maybe there’ll be a story in between the answers to that story."

"Rocket’s past is very important to the present story, but it’s not about how it affects him, it’s about how it affects his relationship with the other Guardians," he added.

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 Kurt Russel. The film arrives in theaters May 5.