Avengers: Infinity War - 12 Plot Twists No One Will See Coming

2. Thanos Turns Good

In the Infinity Gauntlet story, Thanos is undone not by superheroes knuckling down (because he was just way too powerful in the end), but by his own arrogance. Having tasted the almighty power of the Gauntlet, he transcended to a power beyond the limits of his physical body, and unwittingly left the Gauntlet unguarded, for Nebula to take over.

Ultimately, she was tricked into reversing Thanos' deeds and eventually the Gauntlet came into Adam Warlock's possession, unfortunately unleashing his evil side - the Magus - who was so much of a threat that Thanos aligned with Warlock and the Infinity Watch to take him down.

Not all of that is possible in the MCU, thanks to Warlock being set aside for Guardians Of The Galaxy Vol 3, but it would fit that Thanos would over-reach and that Nebula would take on the Gauntlet, losing herself to its power and further threatening existence. And it would be great to see Thanos forced to change his allegiance for the good of the universe (after all, he can't be the most powerful being in the universe without a universe to command) to help defeat her.