Since 2010, Angelina Jolie has appeared on screen only twice: once in her own film By The Sea and once in Disney's Maleficent. So, the announcement that she's joining the Marvel Cinematic Universe not only cements her return to regularly working actress status, but demonstrates Marvel's uncanny ability to woo just about any major Hollywood talent that they want.

Though her co-stars in The Eternals are a talented group, Jolie most certainly brings the most star-power to a franchise that will apparently help to define the fourth phase of the grand MCU experiment. Though, unlike many of the properties adapted during Marvel's imperial phase, The Eternals are far less known amongst general pop culture connoisseurs. Which means the general public doesn't have much reaction to the news other than "Ok, cool!" Comic book fans, meanwhile, apparently accepting that the Marvel film honchos may take a lot more poetic license with the Eternals than more established teams, are a little bit miffed about the circumstances of Jolie's casting.

And, no, it's not because they don't want Jolie in the film. She's not only one of the biggest stars on the planet, but a proven action star thanks to previous work like Tomb Raider and Wanted. Rest assured, the fanboys love her.

It's just that they wanted Jolie to play a character who is even more important to the Eternals mythology.

For those initiated, the Eternals are a race of super-powered, nearly eternal humans who are loosely based on the Greek Gods (somewhat confusingly, however, some actual Greek gods are actually characters in Marvel comic books in their own rights).

Jolie will play Thena, who is both sort of based on and named after the actual Greek goddess Athena (in the comics, Athens, Greece is actually named for Thena, and not Athena). She's a cool character. Like all of the Eternals she has super-human strength, speed, endurance and all that good stuff. She dressed in gold armor. She can fly, move things with her mind, and teleport too. She also has a super-powered bow-and-arrow. Sounds like fun!

The thing is that Thena, in the comics, is a B-list Eternal at best. She sometimes goes against the prevailing line-of-thought of her teammates, and even has an affair with one of their enemies. This isn't all that surprising. Historically, the Eternals comic book hasn't been great to female characters. So much so that three of the characters set to be played by women in the film are actually male in the comics.

The lone exception is a character named Sersi, both the most prominent female Eternals and, just, characters in general. Indeed, early word around the project was that Sersi would be the lead character (alongside Ikaris, to be played by Richard Madden), and many just assumed that Jolie would be playing the part.

Yet, when Marvel introduced the cast at Comic-Con over the weekend, Jolie was introduced as Thena, and Sersi wasn't even mentioned, upsetting some fans.

Of course, if the gender-switching of certain characters isn't already a clue, it seems live Marvel Studios brass will reinterpret these characters for the big screen as they wish. How much they'll stick to the source material remains to be seen.

Though, perhaps Jolie taking a lesser a role isn't a mistake either. She may be returning to taking more roles, but perhaps she didn't want to sign on to devoting the next ten years of her life to the franchise. The potential flexibility of her character gives her a little bit more leeway in that regards. Whoever does end up snagging the role of Sersi (either in this film, or a potential sequel) can deal with appearing in 12 different Marvel movies until 2030, while, theoretically, Jolie would be free to only show up when absolutely needed and continue to attend to her humanitarian work and career as a director otherwise.