Avengers: Age Of Ultron Ending - 14 Implications For Phase 3 And Beyond
3. Thanos Has To Appear In Thor: Ragnarok
If he's done his homework, Thanos should realise that Thor represents one of his mightiest foes. Despite being occasionally pig-headed, the Asgardian is supremely powerful and seems singularly engaged in the quest to find out more about the Infinity Gems.
Could that journey take him to Doctor Strange's door before Ragnarok? Would his alignment with the sorceror be seen by Thanos as a power move that requires him to manipulate the situation on Asgard and pull the world down around Thor's people?
Given that Thor's vision linked the assumed events of Ragnarok (the motif of monsters seems particularly pertinent) with the Infinity Stones, there's a distinct possibility that Thanos is going to be behind the devastation on Asgard. That will presumably act as a cover for his play for the Tesseract, which is still currently on Asgard.