When you look at a particular character on a screen, it’s like observing an iceberg: The bit you see is just a fraction of something that was constructed over a long period, and that goes for every character you’ve ever spent time with. During the lead-up toGuardians of the Galaxy Vol. 3,Chukwudi IwujiandWill Poulterspoke with Collider’sPerri Nemiroffabout building their characters and the background characteristics that help them with their performances.

During the interview, Poulter and Iwuji spoke about how lucky theGuardians of the Galaxycast members are because directorJames Gunndoes a lot of the character-building himself since he also pens the scripts. On top of that, he is also a huge comic book fan—which means building backstories forMarvel and DC characterscomes naturally to him, which is something Iwuji experienced working with Gunn onPeacemaker. At the same time, however, the filmmaker also invites actors to come up with their own ideas as well. That’s how Iwuji conceived the idea that his character the High Evolutionary doesn’t sleep. He broke down the creative process, saying:

Guardians-of-the-Galaxy-Vol-3-The-High-Evolutionary

“There’s that whole incredible history in the comic books of being John Wyndham and whatever, banished from Oxford or Cambridge. It was great to read, but for me, I really like using what’s in front of me and James [Gunn] has this way of creating his own bible for a text, and the beginning, middle, and end is there, all that. What I did use that I would say that I brought into that people don’t necessarily know is that I had an idea that this guy doesn’t sleep. There was something about the royal guy, almost like religious zealotry about him that I go, ‘What if on top of that, he’s so obsessed with his mission, he doesn’t sleep,’ but that was mainly for me and that was what made me feel that whole thing that when I’m in front of people, I turn it on because when I’m not with them, it just goes into a dark morose place, you know?”

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James Gunn EncouragesGuardians of the GalaxyCast Members to Improvise

The terrifyingHigh Evolutionaryis a human who managed to extrapolate the limits of their own body to develop unique mental and psychic abilities. Popular in the comic books, the character is making his Marvel Cinematic Universe debut withGuardians of the Galaxy Vol. 3. The same is true forAdam Warlock, the super-powerful hero Poulter plays. The British actor praised James Gunn’s blueprint for his characters and revealed that his own ideas for the characters he plays often arise after he arrives on set and is able to observe how his fellow cast members interact with each other, which then informs his performance.

The duo also shared that Gunn is very open to seeing how characters naturally develop in a scene, allowing them to try a few takes where he tells the cast to “do whatever” they want. The result is frequently quite positive, as Iwuji explained, “Every now and then, you do something that he really loved, then he pushes it to the nth degree, and that you feel a new scene has come out of the scene that was there. It’s a weird combination for someone to be so prepared, so ready, and at the same time, so flexible, you know? That’s the gift you want as a performer.”

Guardians of the Galaxy Vol. 3premieres in theaters this Friday, May 5. You can watch the trailer below: