Before we get into anything, in you haven't seen Avengers: Infinity War yet for some reason:
There was a really good reason that Hawkeye wasn't included in the marketing for Avengers: Infinity War and that's because he wasn't in the damn movie! He was mentioned once and that's when Black Widow explained that he was under house arrest.
Leading up to the release of the film the creative team teased the character's role in the story. The Russo Bros. said:
"Coming out of Civil War, he’s in the same position that Cap and Falcon are at the end of that movie. And Ant-Man. Coming into this movie, you know… Characters on Cap’s side coming out of the Civil War, some made certain decisions and others made other decisions that led to different paths in them dealing with oversight in this movie in a different way. So Hawkeye’s on his own journey in this movie."
It was explained that "He has a unique reaction to the civil war situation that puts him in a special spot in this film." That special spot landed him under house arrest to be with his family instead of getting back in the fight. That's totally understandable!
When we learned that Hawkeye had a family, that came with more of an understanding of the character and that he has something to lose. In fact, he's one of the few characters in the MCU that has the most to lose. Rocket Raccoon and Ant-Man were the other ones.
During a recent interview with JOE.ie, director Joe Russo talked about Hawkeye's absence explaining that the story that they've come up with for Hawkeye is a "long play".
"We keep saying, 'Patience is a virtue.' We did not forget the twice-nominated Jeremy Renner. We cooked up a story for him that is a little bit of a long play. Not a short play."
So how do the event's of Avengers: Infinity War affect him? Well, at the end of the movie, Thanos did snap his fingers and killed off half of the population of the universe. I can only imagine the worst for Hawkeye in this situation. I think we'll learn that his entire family was killed and that is the life-changing event that will lead to Hawkeye's dark and drastic change that will start him on his journey to becoming Ronin.
It was previously rumored that the events of Infinity War "leaves Barton in a VERY dark place and is the inciting moment in the archer’s shift into this darker superhero mantle. Given the nature of events that cause the shift." Some set photos then surfaced that seemingly confirmed Hawkeye was going the Ronin route.
It just makes sense to me that the tragic death of his family would lead him down this dark path. It makes me even wonder if Avengers 4 will start out with Clint Barton witnessing the death of his wife and kids. That would just be devastating.
I don't care what anyone says. Hawkeye is a great character and I'm looking forward to seeing how his story arc plays out, especially with him taking on the mantle of Ronin. He's just going to get so much more badass.