To fans of Supernatural, "Team Free Will." Refers to the characters Sam and Dean Winchester and Castiel, the main badasses who fought against the destined apocalypse in the show's fifth season. Because screw destiny, humanity can choose what kills 'em and it's not gonna be Satan and dickish angels.
The vernacular arose when Dean sarcastically labeled the three of them in episode 5x13:
Dean: This is it.
Sam: This is what?
Dean: Team Free Will. One ex-blood junkie, one dropout with 6 bucks to his name, and Mr. Comatose over there. Awesome.Fandom
quickly picked up the phrase as shorthand to refer to the three characters as a unit.