Every MCU Villain Ranked Weakest To Strongest
4. Ego
Ego was a Celestial, and one of the oldest and most powerful known beings in the universe. He was also a planet, able to create a human version of himself with the hope of finding purpose in his life. After much soul searching, he decided to create his own universe, but needed a child to help him do it. This led to the birth of Peter Quill, aka Star-Lord.
Ego called his plan the Expansion, and it involved eradicating all life in the universe and replacing it with beings made in his own image. He was able to use his planet to defend himself, creating impenetrable traps, manipulating matter and holding off all of the Guardians' attacks.
He was eventually killed when Groot blew up Ego's brain, saving the universe from the visions of an almost unstoppable madman.