Fans of Marvel Studios are desperate to avoid spoilers, but that didn't stop them from wildly speculating about who would meet their end in Avengers: Infinity War. Fans came to grips with the fact that there would be some - potentially many - sad moments in the movie. In order to prepare themselves mentally for the horrors sure to come when Thanos arrived on Earth, some long-time Marvelites scoured the company’s publishing history, attempting to glean possible indicators of the future from the large number of comic events from years past.
Marvel superheroes do tend to expire fairly frequently in the pages of the comic books (only to return a year or two later), so there was no shortage of potential storylines for Marvel Studios to borrow from. Knowing how a particular Avenger met their doom in the comics didn't make it any easier to experience on the big screen, but it at least gave fans some idea of what happened before seeing the film.
Loki and Thor have spent thousand of years growing up together, and throughout most of that time, Loki is an antagonist. However, on rare occasions, Loki’s love for his brother shines through, most notably when he sacrifices his life to protect Thor and save all of Asgard from The Void. Granted, Loki is responsible for The Void bombarding Asgard in the first place, but he does the right thing when it counts.
Unfortunately, Loki’s sacrificial play is short-lived, as The Void, essentially the evil side of the god-like Sentry, swiftly blows him up, and Thor has to beat The Void anyway. Being a god, Loki does not stay gone for very long.
Early in the events of Civil War II, Thanos comes to Earth seeking the Cosmic Cube, but the Avengers get the drop on him - or so they think. Earth’s Mightiest Heroes somehow manage to underestimate the Mad Titan, which leads to Thanos punching a hole right through the torso of Rhodes, War Machine armor and all.
Some superhero deaths are particularly definitive, and this is one of them. He has yet to return to the pages of Marvel Comics.
Nebula and Thanos have a complicated relationship in the Marvel Cinematic Universe, but their backstory is much more convoluted in the comics. In Marvel Comics continuity, Nebula likely isn’t related to Thanos at all, but claims to be his granddaughter.
Upon his return to life and acquisition of the Infinity Gauntlet, Thanos is less-than-pleased with her claims, and reacts by transforming Nebula into a twisted and miserable being he refers to as “living death.” Nebula, however, gets the last laugh by grabbing the Gauntlet from Thanos and reversing his actions at the culmination of the Infinity Gauntlet storyline.
One of the most unheralded casualties in the comic book version of Civil War is Happy Hogan, Tony Stark’s long-time chauffeur and only real friend. Hogan’s demise occurs on the periphery of the event, as he tries to prevent a villain known as the Spymaster from breaking into a Stark lab. Hogan falls from a great height, and is left comatose and pronounced braindead. Ironically, it is Tony Stark himself who officially ends Hogan’s life, using his techno-wizardry to remotely “pull the plug” on his old friend, sparing Pepper Potts from a difficult decision.