Spoiler warning: This article contains spoilers for Thor: Love And Thunder.
Thor: Love And Thunder proves faithful to the epic comic book run by writer Jason Aaron that introduces Gorr the God Butcher and Jane Foster as Thor, but departs from the source material in one major way. Gorr seeks the Godbomb in the original comics, but in the movie, he seeks Eternity, an all-powerful abstract entity that is the living multiverse.
Comic book fans know Eternity represents the entire multiverse in a single being and plays a role in many memorable storylines, mostly involving Doctor Strange. Eternity's function as the embodiment of the multiverse makes sense given the MCU's focus on the concept, and their debut in the new movie provides another chapter in a growing, complex story that likely leads to Secret Wars.
The Eternity Saga
Comic book fans Eternity first appears in Strange Tales #138, beginning an epic storyline called "The Eternity Saga." Doctor Strange seeks help against Baron Mordo and discovers Eternity in another realm, featuring visually stunning art from Steve Ditko, who co-created the powerful character along with writer Stan Lee.
The quest for Eternity in the comics somewhat mirrors Gorr the God Butcher's in the MCU, but Strange interacts with Eternity, who reveals their identity and purpose in a profound sequence that reverberated through the Marvel Universe for decades.
The Living Multiverse
The multiverse plays a huge role in Phase Four, which is why it makes so much sense Eternity appears now. Eternity exists as the living embodiment of the multiverse, with the power to alter time, space and reality. Perhaps the most powerful cosmic being in the Marvel Universe, Eternity is in effect the Marvel Universe in a person.
Eternity appears as a silhouette containing the cosmos, though at times has taken the form of different avatars in the comics when interacting with other characters, something the new movie utilizes to realize Eternity in the form of Gorr's daughter.
Eternity And Infinity
Eternity formed at the beginning of existence alongside his sister, Infinity. Infinity exists as the living embodiment of space and the twin siblings represent unparalleled power in the cosmos. Infinity and Eternity reign over existence, surpassed only by The Living Tribunal, among the best cameos in Doctor Strange in the Multiverse of Madness.
Infinity herself appears in Thor: Love and Thunder as a statue. A golden monument to her stands in the chamber leading to Eternity, opposite The Living Tribunal and The Watcher.
Eternal Incarnations
Eternity's existence dates back to the Big Bang, but the entity lives and dies with the cosmos itself. As a result, the Eternity in current Marvel Comics serves as the eighth incarnation. The first emerged in the Second Cosmos, the original multiverse that spawned from the First Firmament's destruction at the hands of the Celestials.
Marvel Comics fans know the Celestials play a major role in the creation of the entire Marvel cosmos, and the same appears to be true in the MCU based on lore revealed in Eternals. A Celestial, possibly the first, appears as a statue in the same chamber Eternity occupies in Thor: Love and Thunder.
The Eternity Mask
A unique talisman connected to Eternity may play a role in the MCU. Occultists created the Eternity Mask from Eternity's power in the sixth century as a means to grant the wearer the power of any opponent they face. This proved useful against the original Black Knight, and with Dane Whitman, the second comic book Black Knight now also in the MCU, the mask could appear as well.
The Eternity Mask first appeared in Marvel Comics #1000 in 2019, where its journey through human history to the present day revealed its role in many major events in the Marvel Universe.
Captured By Nightmare
Despite their unrivaled power, Eternity proves vulnerable at times. In Doctor Strange #180, Nightmare, among Doctor Strange's most powerful villains, captures the entity. Nightmare's gambit results in time distorting and Doctor Strange has to try and rescue Eternity from Nightmare's realm.
The story takes a strange twist when the Sorcerer Supreme recruits Juggernaut to help him fight Nightmare, but it proves Eternity's function as almost a Macguffin in and of itself, something that has already occurred in the MCU thanks to Gorr's quest.
Pardoning Galactus
Fantastic Four #262, among the best Fantastic Four storylines the MCU could adapt, features a milestone moment in the Marvel Universe. Reed Richards stands trial for saving Galactus' life, but Eternity arrives to provide cosmic perspective. Eternity, whom Galactus addresses as his father, claims Galactus serves an essential, natural function within the universe.
Eternity turns the image of Galactus as a villain upside down, providing a challenging justification for genocide that led to many moral, ethical, and legal questions for fans, as discussed at Law and the Multiverse.
Fragmenting Eternity
Doctor Strange continues his association with Eternity in The Defenders #92. In this key issue, Eternity summons Strange to help recover different aspects of its essence. Eternity once imbued different beings across the multiverse with fragments of itself, but three went astray. This strange fragmentation potentially plays a role in the MCU.
Eternity later gave birth to several children in the comics in a similar fashion. Eternity created the cosmic entities Empathy, Eulogy, Expediency, Entropy, Epiphany, Enmity, and Eon.
The Death Of Eternity
Eternity lives and dies with the cosmos and in New Avengers #30, the Beyonders killed Eternity along with every other abstract cosmic entity in the multiverse. This shocking moment led to a powerful image where Eternity and Infinity fall with seeming ease, heralding an unimaginable catastrophe.
Eternity's existence in the MCU potentially unfolds as it does in the comics, making its avatar in Gorr's daughter all the more important. She likely becomes the target of beings, possibly the Beyonders or perhaps Kang The Conqueror, seeking to destroy the multiverse.
Secret Wars
Doctor Doom ultimately destroys the Beyonders himself and with their power, remakes the multiverse. Doom inadvertently recreates Eternity when he collapses the multiverse into Battleworld in 2015's Secret Wars, giving the cosmic entity his iconic iron visage in the process.
Doom's ego and power reshape the cosmos, but he does so to save it from annihilation. Many recent developments in the MCU hint at Secret Wars being adapted for live-action, including the concept of incursions, which debuted in Doctor Strange in the Multiverse of Madness.