- "I call it the "Expansion". It is my purpose, and now it is yours as well. Over thousands of years I implanted thousands of extensions of myself on thousands of worlds. I need to fulfill life's one true purpose, to grow and spread, covering all that exists until everything is... me!"
- ―Ego to Star-Lord
- "I was afraid it wouldn't take to the soil but it grew quickly and soon, it will be everywhere, all across the universe!"
Ego became convinced that he was the only last Celestial remaining in the cosmos, presuming his race was an endangered species in the cosmos that was on the verge of extinction. Born bodiless and parentless shortly after the Universe's creation, Ego's origins remains mysterious and unknown by nature; Ego was born as a large brain-like resemblance that was strayed among the stars, while, at the same time, was granted sentience and sapience despite dwelling in extreme loneliness. As he developed over time, Ego molecularly constructed a shell to protect himself and then soon after, Ego molecularly built an equivalent planet-shaped structure to further enhance his self-protection. Throughout eons, Ego remained conscious in solitude watching galactic civilizations rising and falling simultaneously regardless of living in immortality. Yet after bearing witness to death and decay among life in the cosmos, Ego eventually realized that all life other than Ego's life as an near-extinct Celestial was generally futile due to its ephemeral nature. This caused Ego to find what he thought was the actual meaning of life: the proposal to assimilate all life in the cosmos and conquer it for himself.
In many attempts to accomplish this, Ego traveled among the stars to arrive on thousands of life-sustaining planets and implanted thousands of extraterrestrial seedlings (extensions of himself) on all the planets he visited. Once the seedlings are all activated, massive blobs will burst from the planets' soil and initially consume all life-sustaining planets. However this strategy requires an immense amount of Celestial energy to unleash the activation which makes it impossible since Ego cannot locate other Celestials' presence; however, he decided to take the most direct course of action via creating a new race of Celestial hybrids by impregnating thousands of female extraterrestrial species from all life-sustaining planets in the cosmos. Ego hired Yondu Udonta and the Ravagers to deliver his offsprings. The majority of all Peter's unfortunately late biological siblings disinherited the required Celestial DNA for the expansion, which resulted in Ego killing thousands of children due to failing in inheriting the Celestial genes until Ego's biological son, Peter Quill came along as Ego's first son to inherit the Celestial genes. Accompanied by the Guardians of the Galaxy, Quill settled in Ego's planet and later Ego deceived his son by draining Quill's Celestial DNA, flowing down below the planet surface as it was absorbed into Ego's brain, subsequently beginning Ego's terraforming expansion in the cosmos.
The Guardians of the Galaxy fought against Ego to prevent Ego from completing the expansion in the cosmos. To kill Ego, and considering no other options to kill him, the Guardians of the Galaxy had to travel further underground to find Ego's brain and destroy it. While Ego fought Peter Quill, who had at that stage reached a matching god-like status, Groot planted a nuclear bomb on the surface of the brain. Meanwhile, with every chance Ego got to absorb Quill's Celestial power, the planted seedlings expanded dramatically, consuming entire towns and all their constituent lifeforms. Yet the expansion was short-lasting, as Peter Quill stalled his father enough, so that the bomb which was placed on Ego's brain detonated, killing Ego. All of the expanding blobs in the cosmos ceased when Ego died.
When the bomb explodes, Ego dies and the planet collapses. Yondu Udonta gives his spacesuit to Peter Quill to save him, sacrificing himself as he dies in the atmosphere of space. Nebula reconciles with Gamora, but chooses to leave anyway, and the two part as caring sisters. The Guardians give Yondu a traditional Ravager funeral, and dozens of Ravagers, including Stakar Ogord, arrive to pay their respects, releasing a string of fireworks.
- In the comics, Ego attempted to assimilate and make part of himself the planet Earth in various occasions.
|Wars and Conflicts in Earth History|
|First Dark Elf Conflict (Pre-2988 B.C - 2988 B.C.) • Ego's Expansion (Pre-1 A.D. - 2014) • Asgard-Jotunheim War (965 A.D. - 2010) • World War II (1939 - 1945) • Johann Fennhoff's Campaign (1946) • Cold War (1947 - 1991) • Chase of Bruce Banner (2005 - 2010) • Battle of Puente Antiguo (2010) • Aldrich Killian's War (2012) • Chitauri Invasion (2012) • Second Dark Elf Conflict (2013) • HYDRA Uprising (2014) • War on HYDRA (2014 - 2015) • S.H.I.E.L.D. Civil War (2014 - 2015) • Ultron Offensive (2015) • War against the Inhumans (2015) • Inhuman Outbreak (2015 - 2016) • Grant Ward's Campaign (2015 - 2016) • Avengers Civil War (2016) • Erik Killmonger's Campaign (2016) • Uprising in Attilan (2016) • Adrian Toomes' Campaign (2012 - 2016) • Attack on the Sanctums (2017)|