Long ago, Ego decided to spread his consciousness across the universe. To do so, he needed another Celestial’s power to serve as a “seed.” He traveled the galaxy, fathering countless children with different species. None showed Celestial abilities—until Peter. Ego killed every single child and their mothers. Peter’s mother, Meredith Quill, died of a brain tumor Ego planted in her, because he feared falling in love with her would distract him from his mission.
Peter is initially skeptical of Ego's claims, but he eventually comes to believe him. However, Gamora is more suspicious, and she begins to investigate Ego's past. She soon discovers that Ego is not the benevolent being he claims to be, and that he's actually a cold-blooded killer who has destroyed countless worlds. Guardians Of The Galaxy Vol. 2 Kuttymovies
While Peter explores his god-like heritage, the rest of the team deals with their own internal friction: Long ago, Ego decided to spread his consciousness