The Marvel Cinematic Universe has introduced us to various groups of heroes, from the Guardians of the Galaxy hailing from the outer space, to Earth's mightiest heroes, the Avengers, the producer of Eternals, Nate Moore, finally revealed how they are different from the others: they could combine their energies and create a powerful being, the Uni-Mind.
Nate Moore, producer of Eternals, revealed in a set visit by The Direct, that the most unique superpower of the Eternals, making them different from the Guardians of the Galaxy hailing and the Avengers is one of the weird powers vested on them by of Jack Kirby from the comics, the Uni-Mind.
According to Moore, "It allows the Eternals to amplify the power of any single Eternal. However, they all have to be somewhat connected to do so. So they can't be on opposite sides of the world and create a Uni-Mind. They have to be in proximity to each other. It is an amplification device, but it does require the power of all the Eternals together."
In a scene from various trailers, Sersi, Druig, and Makkari are floating in mid-air with golden energy flowing through them, seeming to be linking to each other, and performing some sort of ritual. In the comics, it takes at least three Eternals to merge each other and form the Uni-Mind, also known as the Intellect, wherein they could combine their physical and mental state together into one being, one which could reach the Celestials, their creators.
The Uni-Mind is an immensely powerful psionic entity that is considered by the Celestials to be their greatest gift to their creation, the Eternals. It knows no gender nor race, it is made of pure energy, light, and mind. Usually, it is the Prime Eternal who can summon the said ritual and start the connection to form the Uni-Mind.
It holds various abilities such as cosmic awareness, divine powers, flight, casting illusions, forcefield creations, blast powers, invulnerability and immortality, intellect, psionic energy, superhuman strength and stamina, agility, telekinesis, and telepathy. It only proves that when Eternals come together to will the Uni-Mind, they are as if unstoppable making the most powerful Eternal in the Universe with the combination of at least three of them.
See the Uni-Mind in Eternals on November 5, 2021, only in theaters.