Marvel fans have always had to contend with the fact that rights to the characters and the stories in the comics are divided between 20th Century Fox and Disney. Although Disney holds the rights to majority of the characters, Fox holds the rights to integral characters in the Marvel comics such as the entire X-Men fam.
This division has posed a problem for the stories and timelines. Case in point: Quicksilver, a character portrayed by Aaron Taylor-Johnson in "Avengers: Age of Ultron" and Evan Peters in "X-Men: Days of Future Past" and "X-Men: Apocalypse." Quicksilver is not the only character that will affect both franchises, so do both studios have a fix to this?
Probably so, as in the case of "Guardians of the Galaxy Vol. 2" where a lot of characters thought to be off limits to Marvel Studios made cameo appearances in the film. In an interview with /FILM, Marvel Studios president Kevin Feige revealed how they made this happen.
"There's joint custody with a number of things," Feige explained about the deal. "There are certain characters that they have, but races that we share. If that makes sense?" To be specific, Marvel Studios and Fox have shared rights over The Watchers and the Skrulls, alien races that were first introduced in the "Fantastic Four" comics but also frequent other Marvel comics. The Watchers were featured in a post-credits scene in "GoTG Vol. 2" with its creator, Stan Lee.
The question now, however, is which specific character of these races belong to each studio? For instance, it is presumed that Marvel cannot utilize Super Skrull because the character is a primary antagonist to the Fantastic Four.
It's not impossible for Marvel and Fox to broker a arrangements regarding specific characters. The most recent deal Marvel and Fox entered into was for Ego the Living Planet to be used in "Guardians of the Galaxy Vol. 2," Comicbook reported.
More popularly, Marvel also brokered a deal with Sony to have joint custody of Spider-Man, allowing the character to join purely Marvel properties such as The Avengers in "Captain America: Civil War."