How Marvel Made Avengers: Infinity War The PERFECT Comic Book Movie
3. The Hero Of His Own Story
"The hardest choices require the strongest wills."
Marvel's decision to eschew the Lady Death arc when adapting the Infinity Gauntlet storyline for the big screen was the best possible choice. Whether or not that arc would translate well to the screen is neither here nor there (though Marvel's track record of successfully seemingly unadaptable storylines has been strong), the Lady Death arc simply would not evoke as strong an emotional pull as the arc Thanos is given in Infinity War.
The destruction of his home planet and the extinction of his people motivates Thanos' genocidal quest. For all the destruction it would sow, Thanos believes his doings will bring salvation to the universe. "With all six stones I can simply snap my fingers and it'll all cease to exist. I call that, mercy," he tells Doctor Strange.
Though Thanos wields all of the power of the universe, his appeal is not just that power, nor is it just the threat he poses. Every step of the way, Thanos' conflict is illustrated in powerful, devastating fashion. Only killing when pushed to, his capacity for violence is his last resort tool only used when his quest demands it. An evil only taken when nothing else will do.
Many superhero films in the past have attempted to humanize their villains by justifying their quest as a noble sacrifice towards salvation. Avengers: Infinity War is the first to truly nail this trope, placing great emphasis on the personal sacrifice Thanos' quest catalyzes.