Warning: This article contains spoilers for 'Avengers: Endgame.'

In a recent interview with The New York Times, Avengers: Infinity War and Endgame screenwriters Christopher Markus and Stephen McFeely opened up about which Marvel characters they decided to leave out of the final Avengers movies and why.

The Living Tribunal was one of the characters discussed. While it would have made sense to include the cosmic humanoid character, whose function is primarily to safeguard the Multiverse and prevent any major imbalances (such as having 50 percent of the Earth wiped out, for example), the pair felt it didn't make much sense.

"We did try to put the Living Tribunal in the first movie. We wrote a scene in which he appeared during the Titan fight. And everyone was like, what?" Markus said.

McFeely expanded. "Whoa. He’s got three heads. It would indicate a whole different level of architecture to the universe and I think that was too much to just throw in."

Marvel Studios President Kevin Feige still has final say, Markus adds, before the pair hint that Living Tribunal could show up in another shape or form in the not too distant future.

What's more, X-Men and Fantastic Four characters were also left out because the major Fox (who owned the character rights at the time) acquisition was still in progress while the films were already in development.

“I guess it’s done now but it wasn’t done then,” Markus said, before referencing Dark Phoenix. “They still have an X-Men movie. You can’t reboot them before they’re done. Sorry to completely screw you.”

Find out more about what could be in store for Marvel's superheroes after Endgame here.