WARNING: The following contains spoilers for Eternals, in theaters now.
It's no secret that filmmaker Chloé Zhao is a fan of anime and manga. She grew up with these mediums, even writing fanfiction of her favorite series, and has stated that her "deep, strong, manga roots" played a major part in the development of her Marvel blockbuster Eternals. After watching Eternals, it feels highly likely that one of Zhao's major anime influences has to be Puella Magi Madoka Magica -- and if she somehow hasn't seen that show, then the coincidental similarities are enough that she should absolutely check it out.
Puella Magi Madoka Magica is a dark take on the magical girl genre that took anime fandom by storm when it premiered in 2011. The original 12-episode TV anime has been adapted into movies and manga and received many spin-off stories across multiple mediums. In this series, magical girls fight witches on behalf of an alien race called Incubators. Unbeknownst to the magical girls, the suffering they face ultimately transforms them into witches as part of a cycle of death orchestrated by the Incubators for the sake of harnessing energy to prevent the entropy of the universe.
Eternals is also about a group of warriors fighting monsters on behalf of secretive alien intelligence, the Celestials. Just like the Incubators, the Celestials have orchestrated a cycle of suffering and mass death in the name of extending the existence of the universe as a whole. While the Eternals don't become the Deviants the way magical girls become witches, Eternals and Deviants do originate from the same source.
Thena, the one Eternal who develops Mahd Wy'ry from remembering every cycle of genocide she's engaged in, could be compared to Homura, the magical girl who has lived through multiple timelines and knows far more than her blissfully ignorant peers. Even the orb with which the Eternals' leader can communicate with Arishem the Celestial can be compared visually to the Soul Gems the magical girls are given as the source of their power.
While the themes of Eternals are by no means unique to Madoka Magica, and not even truly new to the Marvel Cinematic Universe, the expression of these themes in some ways feels closer to Madoka Magica than it does to previous MCU movies. Similar to both the Celestials and the Incubators, Thanos in Avengers: Infinity War and Avengers: Endgame also represents a form of utilitarianism taken to a dangerous extreme.
The major difference here is a matter of these villains' perspectives. Thanos' genocide plot is meant as a singular event, justified out of a concern for the individual survivors having enough resources. Both the Celestials and the Incubators, in contrast, operate their plans cyclically, and they don't seem to be particularly concerned with individual perspectives at all so much as the fate of the universe itself. Thanos is a megalomaniac and a narcissist, but Arishem and Kyubey don't operate on human emotions at all so much as a steadfast commitment to their logical yet horrific systems.
Beyond Madoka Magica, it's possible to sense other anime and manga influences in Eternals as well. The idea that human population growth is literally a ticking time bomb for Earth in the face of alien destruction recalls the twist two-thirds of the way through Gurren Lagann. Many of the fight scenes, particularly those involving Kingo's energy blasts, could also be compared to the likes of Dragon Ball and Zhao's stated favorite Yu Yu Hakusho. It's those suffering magical girls, however, that Eternals' plot most firmly recalls.
See the anime-inspired drama of Marvel Studios' Eternals in theaters now.