Warning: Contains spoilers for Avengers #57
The Avengers are supposed to be Marvel Comics' flagship superhero team, the publisher's equivalent of DC's Justice League, but they have been sidelined due to the increasing prevalence of the Multiverse in stories, to the point that the group does not even appear in the latest issue of their own comic book.
The Avengers began as a simple but effective idea: having some of Marvel's already-existing characters team up in shared adventures. This idea of an «ensemble cast» of heroes is very different from, for example, the X-Men or the Fantastic Four, where the characters are created specifically to be part of that team, and the group identity is central. Over the years, the Avengers grew to be Marvel's most popular team, despite their rotating roster, and the whole concept of «the Earth's Mightiest Heroes» became central to their identity. The Avengers are supposed to be the best that Earth has to offer, and for this reason, they are always on the frontlines during Marvel's big events.
Related: Spider-Gwen Exposes the Dark Secret at the Core of Marvel's Multiverse
Despite the Avengers' enduring popularity, however, they have been sidelined in their current ongoing series, which has been focusing on the concept of the Multiverse. The demon lord Mephisto has assembled a terrifying team of multi-dimensional villains called the Multiversal Masters of Evil, and they are conquering one parallel Earth after another. For this reason, many issues in the series have been devoted to showing these alternate universes. Avengers #57, by Jason Aaron, Javier Garròn, and David Curiel, focuses on Sebastian Szardos, the Soldier Supreme, a unique mash-up of WWII Captain America and Doctor Strange,
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