Look, we all know that the Marvel Cinematic Universe can't go on forever in its current form. Unlike pen and ink drawings, actors have to age, and we can't keep getting Captain America movies into the 2030s. So let's talk about the big cosmic elephant in the room. Avengers: Infinity War is coming up, and somebody's gonna die. I don't love the idea, but hey, we're all expecting it, so who's it gonna be? Well, let's look at the potential casualties and figure out who's gonna wind up six feet under Avengers Mansion.
Honorable Mention 1: Drax
Yeah, this one is suuuuuuper unlikely but that's why its an honorable mention and not an entry.
Drax is most likely going to stick around for Guardians 3 at least but if they wanted to kill off one of the Guardians of the Galaxy, he would be the one to go with. Why? Well I'll tell you. Drax is a being driven by rage and revenge. He is The Destroyer. And, while the first Guardians movie re-wrote his origin to make Ronan the one directly responsible for killing his wife instead of Thanos, we already know Ronan did that while working with Thanos.
Plus, if they wanted to adapt it, they could do the whole "Drax's daughter got adapted by Thanos and became Moondragon" thing it would give Drax even more of a reason to want to see Thanos dead. We already know Drax wants Thanos dead, and seeing him go down completing his one true goal would be a tragically beautiful moment. Buuuuut odds are it won't happen.
Odds of death: 1 in 200.
Honorable Mention 2: The Winter Soldier
I mean, it'd sure be shocking.
Yeah, I've been assuming Bucky is gonna be our next Captain America after Steve retires/dies/whatever, but what if he isn't? What if they go with Sam Wilson taking over? Then you got a surplus Bucky to deal with. And killing him off to give Steve a defining motivation to take into the final conflict would be a neat thing to do. Bucky has died in the comics. I mean, obviously, for decades it was the most notable thing about him.
After he took over the role as Captain America from Steve however, he "died" again during Fear Itself, although that was super temporary and mostly just happened so he would go back to being The Winter Soldier again. Which he did. Later he became the Man On The Wall before coming back to be Winter Soldier yet again. Which he is now. He's leading the Thunderbolts, in fact.
Odds of death: 1 in 175.