Directors Joe and Anthony Russo have a lot to answer for when it comes to Avengers: Infinity War, and have tried to justify their reasoning behind killing off so many of the film's heroes. The movie shocked fans with the deaths of  50% of the Earth's population (plants and animals included), along with half of Earth's Mightiest Heroes as well. Fans watched in horror as Spider-Man, Black Panther, Bucky, and more dissolved into dust. Even Anthony Russo himself wasn't spared. These deaths left fans so devastated that Marvel provided emotional support sessions at San Diego Comic-Con.

With a snap of his fingers, Thanos changed the MCU forever. In the end, only the original Avengers were left standing, alongside some lucky additional heroes such as Ant-Man -albeit trapped in the Quantum Realm - and Black Panther's Ramonda and Shuri, who managed to escape with their lives. Avengers 4 will see the survivors picking up the pieces, and ultimately undoing Thanos' master plan.

Related: Infinity War: Why Thanos' Black Order Was So Weak

There's a very specific reason behind all the characters who were sacrificed. In the "Beyond the Battle: Wakanda" featurette on Infinity War's upcoming Blu-Ray and newly available digital release, Anthony Russo explained why certain Avengers died the way they did.

"In terms of our choices about who Thanos would end up eradicating with his snap, it was very story focused. How do we pay off each individual character's storyline most profoundly? The first person to go is Bucky Barnes, and it's shot from Captain America's perspective. You know, we're watching Cap go through the experience of watching [Bucky] go away. We're watching Okoye, whose number one mission it is in life is to protect the king. She watches the king go in front of her. And to see those characters react in those situations is very powerful and resonant."

Tom Holland as Spider-Man and Robert Downey Jr as Iron Man in Avengers Infinity War

So in essence, it seems that their goal was to cause the most amount of pain to fans as possible. Captain America spent two movies trying to save his best friend Bucky. He fought Iron Man and his fellow Avengers just to prove his friend's innocence, only to be forced to watch Bucky vanish before his eyes. Okoye, Wakanda's fiercest warrior, finds herself helpless in the face of her king's demise. Rocket has to watch as Groot dies calling him "Dad" one last time. Wanda has to kill Vision herself before watching Thanos rewind time and kill him all over again. That's not even to mention the saddest death: Peter Parker hugging Tony and announcing the now iconic (and improvised) lines, "Mr. Stark, I don't feel so good" and "I don't want to go." Tony, who has been a mentor and a surrogate father to Peter, can do nothing to protect the fledgling hero.

For the past 10 years,, Marvel has been building up the relationships between these characters on the big screen. In Infinity War the Russos used this to their advantage, taking the closest characters and making one watch as the other dies to create the most gut-wrenching reactions. The deaths would be sad on their own, but they're even worse as seen through the eyes of the survivors. And there is no doubt Captain America, Iron Man, and the others will be feeling survivor's guilt heading into Avengers 4. This could make them stronger and more dangerous foes for Thanos as they work to get back their deceased friends. Just as long as they don't follow the Star Lord way of handling grief.

More: Infinity War Snap 'Permanently' Damaged Thanos & The Infinity Gauntlet

Avengers: Infinity War is available now for digital and streaming, coming to Blu-ray on August 14th.

Key Release Dates