The original Guardians of the Galaxy movie also briefly mentions a Celestial known as Eson the Searcher, who once used the Power Stone to destroy an entire planet.
There are loads of enticing possibilities for the next powerful villain the Avengers will challenge in future MCU movies. The Eternals will introduce immortal beings tasked with protecting humanity from their villainous counterparts, the Deviants. There’s evidence to suggest the Deviants could be the next major threat to Earth’s Mightiest Heroes, but some even more powerful entities would be natural antagonists for Avengers 5.
First introduced in the 1976 comic Eternals #2, The Celestials are essentially the mythological Titans of the Marvel universe. They’re ancient entities with immense and seemingly omnipotent powers and are responsible for creating the Eternals and the Deviants, both of whom were early experiments in the evolutionary process on Earth.
Occasionally referred to as space gods, the Celestials are known for their obsession with the Infinity Stones. While they’re not exactly prominent characters in the MCU, their presence has been established on the periphery of major events affecting the Avengers and their allies.
Ego the Living Planet, aka Star-Lord’s dad, is a Celestial. That alone is pretty solid proof that these powerful beings have been to Earth before. The original Guardians of the Galaxy movie also briefly mentions a Celestial known as Eson the Searcher, who once used the Power Stone to destroy an entire planet. , a location created from the head of a dead Celestial, appears in Thor: The Dark World, Guardians of the Galaxy, and Infinity War.