Jack Kirby and Stan Lee are responsible for shaping modern mythology and pop culture during their historic collaboration in Marvel Comics print media. They are the all-fathers of a sprawling multiverse, and at its center are the Celestials, a race of beings who were ancient at the dawn of time, and who have served as shepherds of all intelligent life in existence across the entirety of reality.
Referred to as Space Gods among those sentients schooled in galactic lore, the Celestials are harbingers of creation and annihilation, and the Eternals film trailer just introduced two important additions to this primordial cosmic pantheon. Jemiah the Analyzer and Arishem the Judge. They are two among many, though how many is unknown, but Kirby engineered an entire mythology around the Celestials and their planetary pilgrimages, referred to as "Hosts."
The First Host
The Celestials search out worlds during their biological cognitive infancy. Marshaling intellect and instruments far beyond the ken of mortal understanding, they conduct experiments on the native bio-forms who carry markers for evolutionary potential. Once a selection is made, the Celestials radically alter the genetic building blocks of these prospects, then leave the planet to allow for the species to develop along the new chosen path. They may also leave monoliths across the planet that serve as catalyst engines for further rapid biological advancement. One million years ago they visited Earth and chose a primate, the Dawn Ape, to genetically alter in this fashion and this gene editing resulted in three unique progenitor species.
Possessing an unstable genetic structure, the Deviants (Homo descendus) were barbarous psychotics who sought dominion over the world. They enslaved mankind, made war upon the Earth and all its people, and sought scientific solutions that might stabilize their erratic DNA. They lived their lives beneath the Earth and raided the surface when their needs or whims dictated.
The Eternals (Homo immortalis) were crafted as gods among men. Embedded with a mandate to protect the Earth on a molecular level, the Celestials gave them abilities worthy of their charge, including eternal life. Though they reproduce at a fraction of their ancestral cousins, their power overcompensates for what they lack in numbers. Flight, invulnerability, energy manipulation, telepathy, and global communion are traits each Eternal carries in addition to other specialized powers like super speed or shape changing.
Humanity (Homo sapiens) were the baseline branch, flawed and ambitious, but also pregnant with genetic latencies that would respond to specific types of radiations inherent to a technologically maturing planet. As the Earth entered the mechanical age, these ambient energies were abundant and begun to express themselves in the genomes of mankind. Individuals like Bruce Banner, Steve Rogers, and the explorers who would become the Fantastic Four were inundated with these atomic wavelengths which subsequently triggered dormant genes, imbuing each of them with immense power. Absent Celestial manipulation, they would have simply been destroyed by these powerful forces. This "X" gene, however, also expressed itself as spontaneous mutations within the human diaspora. Apocalypse, Charles Xavier, Jean Grey and Ororo Munroe are all the progeny of the Celestial's experiments, representing a brand new branch of humanity, Homo superior.
Second Host
During the next hundred years or hundred millennia, the Celestials would continue their experimentations across the multiverse. Eventually they would return to check on the progress of their experiments, which usually meant the destruction of a species or even an entire world. In Earth's case, the Second Host took place 25,000 years ago. The Deviants ruled the Earth employing modern technology, in spite of the Eternals presence, and fired upon the Celestials as they pierced the upper atmosphere. The Celestials destroyed their empires so utterly that continents sank and the Earth's mantle spasmed. A remnant of humanity survived, guided by a lone Eternal to safety, where they built the beginnings of a new civilization.
Third Host
One thousand years ago the Celestials returned for the Third Host, convening in Peru amongst the majesty of the Incan empire, to study the man's progress. The assorted gods of mankind, Zeus, Vishna, and Odin, father of Thor and Loki, were so threatened by their presence that they fought the Celestials much as the Deviants had thousands of years prior. The results were similar. The unified deities of Earth were not able to injure the Space Gods in any way whatsoever. Humiliated and defeated, the fallen gods paid a price for their folly. They were forbidden for interfering in the affairs of Earth from that moment on and thus disappeared from the lives of mankind.
Fourth Host
In the near present day, the Celestials returned once more, to see what flowers had grown in their irradiated garden. Though Odin had kept to his word, and sacrificed much to keep Thor away from Midgard (Earth) and its people, he had not been idle. He fashioned the Destroyer and the Odin Sword to vanquish the Celestials once and for all, one thousand years in the making. After a futile battle reminiscent of the one fought a millennia ago, all of the Asgardian King's machinations were brought to ruin and only the judgment of the Celestials themselves could save the Earth.
The Celestials
A single Celestial can lay waste to an entire galaxy. Every category of power they possess, strength, endurance, intelligence, energy control and absorption, all of them are beyond the ability to measure. At the dawn of the universe a Celestial experiment gone awry resulted in a powerful nexus of creatures that stretched even their ability to control. As a means to imprison them, through sheer force of will, the Celestials split the universe into a multi-verse. Each Celestial is capable of omni-presence, the ability to occupy more than one physical space simultaneously across vast distances, without any loss of power or capability.
Every civilization in the universe and every near god of record, such as Galactus or Thanos, fear the might of the Space Gods.
Despite their vast power, children of Earth have harmed and even defeated Celestials in combat. Thor once summoned enough power to crack the armor of a Space God. He entered inside and found himself in an extra-dimensional space patrolled by powerful "anti-bodies" seeking to immunize themselves of the Thunder god, but not before he was able to rock the Celestial on its feet from the inside. Jean Grey, while employing the Phoenix force, was able to sever a Celestial's hand, though it immediately regenerated. The Invisible Woman also pierced the hull of a Celestial and actually succeeded in destroying it after collapsing its "nerve center."
Humanity's ability to achieve these miraculous feats, among others, once had the Time Keepers consider erasing them from the sacred timeline altogether. Ironically, these exact exploits may be the activated potential the Celestials set in motion a million years ago.
Jemiah the Analyzer
Each Celestial has a specialized role in their cosmic work. Jemiah the Analyzer works in concert with other Celestials, most notably Gammenon the Gatherer, to ascertain the fundamental properties of life on a given planet and perhaps even speculate, after examination, upon its raw potential. The Skrulls, similarly cultivated by the Space Gods, at one point tried to destroy him with their worldwide planet killing tech that left him standing unharmed in a smoking crater.
The glimpse provided in the trailer doesn't divulge much about what his role in the film may be, but it does display him shaping energies and appearing through a rift in space, arriving for some unknown purpose.
Arishem the Judge
Arishem the Judge literally holds the fates of worlds within the palm of his hand. Written in glyphs known only to themselves, the equation for global destruction is inscribed along his thumb. Like Roman emperors of antiquity, Arishem silently twists his wrist and civilizations are either eradicated or given a stay of execution. It's been noted that out of the trillions of worlds in existence only a handful have ever proven worthy of further study, Earth principal among them.
His appearance in the film differs greatly from his depiction in the comics which breaks with precedent in the Marvel Cinematic Universe. Eson the Searcher, another Celestial, was featured in Guardians of the Galaxy and modeled precisely on Kirby's blueprint. Arishem appears to be a hybrid of Eson, Gammenon, and Hargen the Measurer. This may be a purely artistic choice or a nod to additional portfolios of responsibility and power.
Eternals releases in theaters only on Nov. 5.