Guardians Of The Galaxy Vol. 3: Everything We Know
6. Adam Warlock Will Be Involved
While the story of Guardians 3 is a complete mystery at this point (besides the obvious, like the involvement of the core Guardians crew), we do know one major element that's likely to be a big part of it: Adam Warlock.
The character first appeared on the pages of Marvel Comics in the late '60s, and debuted in the MCU - in cocoon form - in one of Guardians 2's post-credits scenes. This obviously indicated that the character would appear in Guardians 3, which was all-but confirmed by Gunn in April 2017, when he told Slash Film that Warlock would appear "later".
He also told the outlet that Warlock was initially in Guardians 2, but had to be cut because he was "one character too many". We don't know how the character will factor into Guardians 3, but with Gunn going deep on his Warlock research (via Screen Rant), it's safe to assume that he'll have an important role to play, both in the third Guardians film, and beyond.