Question: What character who is a former member of the Avengers was played by Pom Klementieff in Guardians of the Galaxy Vol. 2?

Context paragraphs:
Pom Klementieff: Pom Klementieff (born c. 1987) is a French actress.  She was trained at the Cours Florent drama school in Paris and has appeared in such films as "Loup" (2009), "Sleepless Night" (2011) and "Hacker's Game" (2015).  She plays the role of Mantis in the film "Guardians of the Galaxy Vol.  2" (2017) and will appear in the same role in the film "" (2018).

Untitled Avengers film: The untitled Avengers film is an upcoming American superhero film based on the Marvel Comics superhero team the Avengers, produced by Marvel Studios and distributed by Walt Disney Studios Motion Pictures.  It is intended to be the direct sequel to 2018's "", as well as the sequel to 2012's "Marvel's The Avengers" and 2015's "" and the twenty-second film installment in the Marvel Cinematic Universe (MCU).  The film is directed by Anthony and Joe Russo, with a screenplay by Christopher Markus & Stephen McFeely, and features an ensemble cast that includes Robert Downey, Jr., Josh Brolin, Mark Ruffalo, Tom Hiddleston, Chris Evans, Chris Hemsworth, Jeremy Renner, Chris Pratt, Elizabeth Olsen, Benedict Cumberbatch, Evangeline Lilly, Karen Gillan, Anthony Mackie, Tom Holland, Zoe Saldana, Dave Bautista, Paul Bettany, Scarlett Johansson, Jon Favreau, Gwyneth Paltrow, Sebastian Stan, Don Cheadle, and Pom Klementieff.

Avengers: Infinity War: Avengers: Infinity War is an upcoming American superhero film based on the Marvel Comics superhero team the Avengers, produced by Marvel Studios and distributed by Walt Disney Studios Motion Pictures.  It is intended to be the sequel to 2012's "Marvel's The Avengers" and 2015's "" and the nineteenth film installment in the Marvel Cinematic Universe (MCU).  The film is directed by Anthony and Joe Russo, with a screenplay by Christopher Markus & Stephen McFeely, and features an ensemble cast that includes Robert Downey Jr., Josh Brolin, Mark Ruffalo, Tom Hiddleston, Chris Evans, Chris Hemsworth, Jeremy Renner, Chris Pratt, Elizabeth Olsen, Sebastian Stan, Benedict Cumberbatch, Paul Bettany, Cobie Smulders, Benedict Wong, Zoe Saldana, Karen Gillan, Vin Diesel, Dave Bautista, Bradley Cooper, Pom Klementieff, Scarlett Johansson, Benicio del Toro, Tom Holland, Anthony Mackie, Chadwick Boseman, Danai Gurira, Paul Rudd, and Don Cheadle.  In "Avengers: Infinity War", the Avengers join forces with the Guardians of the Galaxy to confront Thanos, who is trying to amass the Infinity Stones.

Gamora: Gamora Zen Whoberi Ben Titan ( ) is a fictional character appearing in American comic books published by Marvel Comics.  Created by Jim Starlin, the character first appeared in "Strange Tales" #180 (June 1975).  Gamora is the adopted daughter of Thanos, and the last of her species.  Her powers include superhuman strength and agility and an accelerated healing factor.  She also is an elite combatant, being able to best most of the opponents in the galaxy.  She is a member of the group known as the Infinity Watch.  The character played a role in the 2007 crossover comic book event "", and became a member of the titular team in its spin-off comic, "Guardians of the Galaxy".  She has been featured in a variety of associated Marvel merchandise.  Zoe Saldana plays the character in the 2014 live-action film "Guardians of the Galaxy" and its sequel "Guardians of the Galaxy Vol.  2".

Guardians of the Galaxy Vol. 2: Guardians of the Galaxy Vol.  2 is a 2017 American superhero film based on the Marvel Comics superhero team Guardians of the Galaxy, produced by Marvel Studios and distributed by Walt Disney Studios Motion Pictures.  It is the sequel to 2014's "Guardians of the Galaxy" and the fifteenth film in the Marvel Cinematic Universe.  The film is written and directed by James Gunn and stars an ensemble cast featuring Chris Pratt, Zoe Saldana, Dave Bautista, Vin Diesel, Bradley Cooper, Michael Rooker, Karen Gillan, Pom Klementieff, Elizabeth Debicki, Chris Sullivan, Sean Gunn, Sylvester Stallone, and Kurt Russell.  In "Guardians of the Galaxy Vol.  2", the Guardians travel throughout the cosmos as they help Peter Quill learn more about his mysterious parentage.

Mantis (Marvel Comics): Mantis is a fictional character, a superheroine appearing in American comic books published by Marvel Comics.  The character is a former member of the Avengers.

Guardians of the Galaxy Vol. 2 (soundtrack): Guardians of the Galaxy Vol.  2: Awesome Mix Vol.  2 (Original Motion Picture Soundtrack) is the soundtrack album for the Marvel Studios film "Guardians of the Galaxy Vol.  2".  Featuring the songs present on Peter Quill's mixtape in the film, the album was released by Hollywood Records on April 21, 2017.  A separate film score album, Guardians of the Galaxy Vol.  2 (Original Score), composed by Tyler Bates, was also released by Hollywood Records on the same date.

Laura Haddock: Laura Jane Haddock (born 21 August 1985) is an English actress.  She is best known for portraying Kacie Carter in "Honest", Lucrezia in "Da Vinci's Demons", Meredith Quill in "Guardians of the Galaxy" and its sequel "Guardians of the Galaxy Vol.  2", Alison in "The Inbetweeners Movie" and Viviane Wembly in "".

Guardians of the Galaxy (film): Guardians of the Galaxy (retroactively referred to as Guardians of the Galaxy Vol.  1) is a 2014 American superhero film based on the Marvel Comics superhero team of the same name, produced by Marvel Studios and distributed by Walt Disney Studios Motion Pictures.  It is the tenth film in the Marvel Cinematic Universe.  The film was directed by James Gunn, who wrote the screenplay with Nicole Perlman, and features an ensemble cast including Chris Pratt, Zoe Saldana, Dave Bautista, Vin Diesel, Bradley Cooper, Lee Pace, Michael Rooker, Karen Gillan, Djimon Hounsou, John C. Reilly, Glenn Close, and Benicio del Toro.  In "Guardians of the Galaxy", Peter Quill forms an uneasy alliance with a group of extraterrestrial misfits who are fleeing after stealing a powerful artifact.

Karen Gillan: Karen Sheila Gillan (born 28 November 1987) is a Scottish actress, director, and screenwriter.  She is known for the role of Amy Pond, companion to the Eleventh Doctor, in the BBC science fiction series "Doctor Who" (2010–13).  In film, she has starred as Jane Lockhart in "Not Another Happy Ending" (2013), Kaylie Russell in the horror film "Oculus" (2013), and Nebula in the Marvel film "Guardians of the Galaxy" (2014) and its sequel "Guardians of the Galaxy Vol.  2" (2017).  She took part in the upcoming films "" (2017), "" (2018) and its untitled sequel (2019).  In 2017, she wrote and directed her first feature film, "The Party's Just Beginning".

Supporting paragraphs: Pom Klementieff Mantis (Marvel Comics)
Answer: Mantis