Ego

Ego also known as the Living Planet is the true main antagonist of Guardians of the Galaxy Vol. 2

Role
Ego is the Biological Father of Peter Quill. He comes into contact with Peter and his friends after locating them on berhert. He Stays with them the night in the woods before inviting them on his planet the Next day. The Next Morning they leave to go to Ego's planet leaving Behind Rocket, Groot and Nebula. They arrive on ego's planet and he explains his origins. After a tour he overhears Peter and Gamora talking about him and Gamora saying he might be a threat to which Peter starts an argument. Later he teaches Peter how to use his celestial powers and they end up playing Together. Later ego reveals to Peter that he killed Meredith because he knew if he returned to her he would never leave her to go back to his planet. He battles the Guardians that noon and dies.

Trivia
in the comics, he wasn't Peter's father.