Thanks to the enormous critical and box office success of Marvel's "Guardians of the Galaxy" last summer, comic book fans have been dreaming up potential characters and plot lines for the sequel for almost a year now. Ideally, everyone's favorite Marvel characters would be able to make some type of appearance at one point or another. Unfortunately, that's not the reality of the current Hollywood landscape.

Director James Gunn has noted that different studios own the rights to different characters, making it difficult to include fan-favorites into certain films. Specifically, this means no Shi'ar Empire or Kang The Conqueror in the Marvel Cinematic Universe anytime soon.

"Shi'ar and Kang are both owned by Fox. All decisions about who is in GotG2 were made a long time ago," Gunn wrote on his Facebook.

It's smart of Fox to snatch up popular villains such as those two, especially given their connections to the existing Marvel properties owned by Fox. Kang The Conqueror has long been a primary antagonist for the Fantastic Four and the X-Men. The Shi'ar Empire has also been featured as enemies in X-Men comics.

Rumors have been circulating for a while now that Fox is planning an eventual crossover for their Fantastic Four and X-Men universes. Having, these two villains on the roster will make that easier.

Marvel, meanwhile, still has the rights to piles and piles of famous bad guys, so they won't be hurting in that department.

"Guardians of the Galaxy 2" is set to hit theaters on May 5, 2017.