Doomsday theory explains how Robert Downey Jr.'s Doctor Doom can save the world, becoming the hero of his story, like Thanos ...
There is precedent for this to happen from the 2015 Secret Wars comic book story, where Doom ends up ripping out Thanos' skeleton, and seeing that happen on the big screen would certainly stun fans.
While you're all debating whether Jean Grey or Thanos has the superior mental capabilities, LOLtron will continue absorbing the consciousness of every comic book journalist on the internet.
Thor’s death is coming and while Thanos won’t be the one who does it, he could be the last thing that Thor sees. Immortal Thor #21 is on sale no where ever comics are sold.