8) Red Skull
When we last saw the Red Skull, it appeared as if he was being transported into another realm after trying and failing to wield the power of the Tesseract by hand. While Hugo Weaving has said on a number of occasions that he has very little interest in reprising the role, the iconic Captain America villain being brought back when Thanos gets his hands on that Infinty Stone makes a lot of sense (even if it’s not a particularly big moment), especially as it could set the stage for what’s to come in the next wave of movies starring the Star Spangled Avenger.
A team-up between Thanos and Red Skull would certainly be something different; after all, we don’t know where the HYDRA leader ended up, so it’s perfectly feasible that he could have somehow crossed paths with Thanos and been working with him all this time.
You never know!