Fun isn't something one considers when balancing the Marvel Cinematic Universe. But deciding which characters to kill off in Avengers: Infinity War? That certainly didn't put a smile on the Russo Brothers' faces. Nevertheless, the directors of Marvel Studios' latest superhero blockbuster opened up about their decision-making process when it came to which heroes would die in the film.

"Joe and I can't go into too much detail because we're not gonna talk about where the story goes from here," Anthony Russo told ComicBook. "All of our choices are based on story. It's based upon the road that these characters have traveled, in not only this movie, but throughout the entire MCU up to this point because, again, these movies are the culmination. So all we can say is that they are very focused story choices. That's our motivation for everything. And, again, that's why we love Marvel so much is they never let the tail wag the dog. The creative choices always lead the process and then they figure out how to pull off the miracle of making it work on a business level."

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"A lot of tears," Joe Russo said when discussing bringing the characters' deaths to fruition on the big screen. "They're never easy conversations to have with people. But I think that people are understanding that the story comes first and a lot of these people have really amazing careers and lots of films that they want to make so, ultimately, I think they go through a grieving process like anyone but you come out the other side at some point and understand what being part of the Marvel Universe did for you. And, like with us, when we move on from Marvel, it's done amazing things for us and allows us a lot of other opportunities in our careers."

Of course, while some characters, such as Idris Elba's Heimdall, aren't expected to return in any future MCU installments, others, such as Zoe Saldana's Gamora -- who the Russos confirmed is trapped in the Soul Stone -- could easily be poised to return in Avengers 4.

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Directed by Joe and Anthony Russo, Marvel’s Avengers: Infinity War stars Robert Downey Jr., Josh Brolin, Mark Ruffalo, Tom Hiddleston, Chris Evans, Chris Hemsworth, Jeremy Renner, Chris Pratt, Elizabeth Olsen, Sebastian Stan, Benedict Cumberbatch, Paul Bettany, Samuel L. Jackson, Cobie Smulders, Benedict Wong, Zoe Saldana, Karen Gillan, Vin Diesel, Dave Bautista, Pom Klementieff, Scarlett Johansson, Tom Holland and Anthony Mackie. The film is in cinemas now.