Who Kills Thanos? - Predicting Avengers: Infinity War's Climax

5. No-One

While there's lots of talk of how the Avengers and Guardians Of The Galaxy will manage to defeat Thanos, if Marvel decide to closely adapt the Infinity Gauntlet story for Thanos' "end," Infinity War cannot include his death in those terms.

In the comics, Thanos is undone by his own arrogance when he takes on an astral form and abandons his physical body, leaving the Infinity Gauntlet unattended. He then ends up allying himself with the remaining heroes to stop the Gauntlet's ultimate threat to the universe. So in essence, he's never really defeated and when he decides to retire peacefully, it's on his own terms.

That would be a bold decision by the Russos, but it would fit with the fact that any single entity defeating him with the Gauntlet fully-powered is somewhat unlikely. And there's also the fact that his intent is fundamentally a "good" one as he wants to save the universe from itself, so he could be convinced to turn on his initial plans, given the right motivation.

That might not be as popular with fans - and nor would it fit Marvel's usual model for dealing with villains - but there's certainly a sense that it would fit.