This Eternals leak from 4Chan was posted yesterday, but I can't find the link for it. I think it got deleted. I don't trust 4Chan but everything I read here looks factual:

Thousands of years ago, the Celestials came to Earth and experimented on humans, creating Deviants and Eternals. Deviants are purple, mindless monsters, and Eternals are humanoid gods with magical abilities. For years, both species fought for dominance in the cosmos.

The main planet for Eternals is Olympia, after Titan fell. Eternals are forbidden from having children or mingling with humans. Eternals thinklowly of humans and deem themselves superior.

Sersi (Gemma Chan) is a naive and childish soldier who relishes interacting with humans.
Ikaris (Richard Madden) is the most powerful Eternal in Olympia who is married with two kids.
Makkari (Lauren Ridloff) is a mute and deaf speedster who is discriminated against in this society.
Phastos (Brian Tyree Henry) is the mostintelligent man in the city, who builds weapons and armor despite being a pacifist.
Kingo (Kumail Nanjiani) is the comedic relief and a refugee from Titan, who is an expert swordsman.
Thena (Angelina Jolie) is a mysterious and aggressive commander of the Olympian military.
Gilgamesh (Don Lee) is an extremist who is exiled from the city after leading a failed uprising.
Druig (Barry Keoghan) is a loner and a refugee from Titan.
Ajak (Salma Hayek) is the matriarch of the Eternals who can heal with a kiss.

The Eternals recieve news about the activities ofEarth from a Black Knight, a servant who wields the Ebony Blade and guards humanity from the Deviants when the Eternals are occupied. The Black Knight of this generation is Dane Whitman(Kit Harrington). Him and Sersi fall in love. Ajak forbids the relationship. Sersi enlists the help of Sprite (Lia McHugh) for wisdom. Sprite says thatthere is an ancient gravesite called the Tomb of the Gods that is enchanted with Asgardian magic that can grant the wish of anyone who wishes for it, as long as they deliver the Ebony Blade. Sersi steals it from Dane and wishes for her to become human.

The spell works but quickly backfires. Instead ofjust Sersi becoming human, Makkari, Phastos, Kingo, Sprite, Druig, Ikaris, and Thena become human as well, and they do not remember their past lives. Dane Whitman is also no longer the Black Knight but an archeologist. In this new reality, Gilgamesh's uprising succeeded, and theEternals have become world conquerors all around the galaxy, and Ajak is exiled.Sersi is the only one whose memories are intact,and she discovers that there are Deviants on Earth, and Gilgamesh's forces are arriving. To prevent a mass war, Sersi must find her friends and jog their memories to prevent a catastrophe.It is revealed that Sprite tricked Sersi. She wished for all the Eternals to become human long ago, but she didn't have access to the Ebony Blade. Instead of the Tomb fulfilling Sersi's wish, it just simply granted Sprite's since she asked first. She was tired of being treated like a kid.The story has numerous flashbacks to the past. We will see ancient civilizations both on Earth and in space. We will see a young Odin and a young Thanos.