Karen Gillan's Nebula will have a lighter personality, the actor teased. Reports Variety.
"She had a very cathartic experience with having Thanos eliminated from her life. So she's finding her own personality," she said.
Pom Klementieff teased the following for Mantis: "She's still quirky and weird but at the same time, she shows a lot of confidence and she shows some fighting skills maybe."
"I'm truly, truly grateful," Poulter said about playing Adam Warlock.
"It's pretty surreal to have ever stepped on the 'Guardians' set."
'Guardians of the Galaxy Vol. 3' is directed by Gunn, who helmed the first two cosmic team-up films, and it reunites the entire team, plus some new faces.
The cast includes Chris Pratt as Star-Lord, Zoe Saldana as Gamora, Dave Bautista as Drax the Destroyer, Bradley Cooper as Rocket Raccoon, Vin Diesel as Groot, Karen Gillan as Nebula, Pom Klementieff as Mantis, Sean Gunn as Kraglin and Elizabeth Debicki as Ayesha.
"The most rewarding part of it has been working with my brother," Sean Gunn told Comic-Con about the film."
"It's come to a point where it's not just about the joy of working with him, it's about the joy of working with all these other people. We f***ing care."
Poulter, who's starred in 'The Revenant', 'Midsommar' and just earned an Emmy nomination for 'Dopesick', plays Adam Warlock. In the comics, Adam is an all-powerful, artificial being created to destroy the Guardians of the Galaxy.
Also among the cast is Chukwudi Iwuji, who worked with Gunn on his 'Peacemaker' series, and Daniela Melchior, who played Ratcatcher II in Gunn's 'The Suicide Squad' last year.
The Guardians of the Galaxy most recently appeared in the opening to Taika Waititi's 'Thor: Love and Thunder'.
After Thor and the Guardians teamed up in 'Avengers: Infinity War' and 'Avengers: Endgame', they kept travelling together to help save various alien worlds from threats, but Thor eventually splits off on his own mission.
It's taken a while to get the third 'Guardians of the Galaxy' movie made.
Back in 2018, Disney fired Gunn after controversial Twitter posts resurfaced, only to rehire him a few months later after he apologised.
'Guardians of the Galaxy Vol. 3' will hit theatres on May 5, 2023.