Marvels Eternals was a DOA franchise wannabe when it arrived in 2021. The cosmic drama didnt click with audiences, and despite post-credits stingers with loads of setup, its no longer part of the studios current unfolding saga. Kevin Feige gave the update this summer that there are no immediate plans for Eternals 2.But in the Marvel Cinematic Universe, even a dud makes an impact. At the end of Eternals, the godly superhero team defies its towering space leader Arishem by preventing the birth of a new Celestial, Tiamut, who will pop out of their incubation chamber, aka the Earth. The delay of the Emergence seemed to upend the status quo of the universe (Arishem literally grabbed a few of the Eternals off the planet to prove humanitys worth), but as far as the tangible goes, it left a big stone hand jutting out of Earths ocean.The hand was big enough that Marvel couldnt sweep it under the rug. In 2022, She-Hulk poked fun at the impossible-to-miss plot-dangler. Captain America: Brave New World will directly deal with it next February. What If? season 3 is the latest property to indulge in what Eternals left behind, and in more ways than one. Frankly, its acknowledgement that the movie deserves as it fades further into the annals of Marvel history.In What If Agatha Went to Hollywood? the second of What If?s new batch of episodes, Agatha Harkness (Kathryn Hahn) is a Golden Age movie starlet lighting up the screen under director Howard Stark. Shes also still a witch hungry for power, and her next move is to siphon the cosmic abilities of fellow actor Kingo (Kumail Nanjiani). Her plan comes together when Stark Pictures recruits the Bollywood star for a whiz-bang musical number turns out, Agatha can dance as well as she can sing and by the end of the showstopper, the two have brokered a deal to summon and defeat Arishem.Eternals doesnt just grant the Marvel stories the chance to drop a few references and cameos. The big swing writer-director Chlo Zhao took in melding mind-bogglingly epic ideas about gods and creation with multicultural customs and culture from around the globe allows a show like What If? (and hopefully future Marvel movies) to stretch its visuals way beyond the house style of an Avengers movie. A glittering, fire-blasting musical number is right at home in this weird, wonderful MCU tapestry, as well as a fight between two titans in space.When Agatha absorbs Kingos power, she transforms into a deity worthy of punching Arishem square across the jaw. In the grand tradition of characters entering the spirit plane and whupping ass as kaiju, Celestial Agatha eclipses the entire Earth to take on the Judge of the cosmos, and, like in Zhaos film, the camera often swoops down to ground level on Earth to see just how much the two dwarf the planetary battleground. Its big and capital-A Awesome.Episode 2 is not the only Eternals connection in the final run of What If?: An episode later in the season directly deals with the Emergence, this time wondering what would happen if the Eternals failed and Tiamut shattered the Earth on his way out the door. Thats just the beginning no spoilers, but things get way, way, way wackier from there but the entire What if? is predicated yet again on groundwork set by a movie that, based on Feiges comments, is being dealt with rather than appreciated.Zhaos vision for Eternals clearly did not fit the trajectory of the Marvel Cinematic Universe, one of references, recastings, and Deadpools versus Wolverines. But it did move the needle. What If? may not be canon, but its been a testing ground for ideas that did cross over, from Doctor Stranges multiversal madness to Captain Carter (who may graduate from cameo to full-blown action hero in Avengers: Doomsday). If Eternals is on the minds of those playing in the sandbox, theres still some hope for us defenders of the film that its mythology may trickle throughout the future.If Eternals legacy doesnt manifest in Fantastic Four (is this Galactus a Celestial?) or Secret Wars (something something Harry Styles as Eros?) then Marvel certainly seems content in toying with my emotions. The end of What If Agatha Went to Hollywood? delivers a beat that is basically rude for the final season of a series that, at least by the two-part finale later this week, promises not to pick up any loose ends set by other episodes.This has probably drawn the Celestials attention, Kingo says of Agathas destructive battle with Arishem. The bad kind of attention.Agatha shushes him now is the time to celebrate, not dwell on existential horrors to come.We can save that for the sequel!Eternals isnt getting one of those. Agatha All Along isnt even guaranteed to get a second season (let alone the big-screen treatment that Agathas power set clearly deserves after this episode). So who knows where or how or if this non-canon storyline will ever get a proper sequel. But what seems true is that by playing god in the MCU, Zhao and her film have made Eternals a required consideration for future Marvel stories. And if that means more A-list actors muttering Arishem the Judge across 4,000 summer-weekend screens well, that might be enough to make up for a lack of Eternals 2.