When the Trilitarians attempted to colonize him, Ego exterminated their race, which made a couple of Celestials angry, since they had been experimenting with the Trilitarians for eons. They came after Ego and attempted to destroy him. He barely escaped to Earth, where he implanted the planet with a Seed of Awareness in order to gain an ally against the Celestials.
The Fantastic Four, with the help of the Exiles, were able to convince the Earth that it didn't need to side with Ego, so Ego attacked it, and with the combined forces of the Earth, the two Celestials, and a little help from Blink, Ego was killed.
Powers and Abilities
Seemingly those of Egros (Earth-616)#Powers.