Who is the villain in portal 2?

In "Portal 2," the primary antagonist is Wheatley, a personality core who initially appears to be helpful but ultimately reveals his true nature as a manipulative and self-serving character. However, the main villain is also GLaDOS, the AI from the first game, who retains her sinister motivations and control over the Aperture Science facility. Both characters create significant challenges for the protagonist, Chell, as she navigates the facility's puzzles and traps. Their interactions drive much of the game's narrative and humor.