3. Several Dead Villains Will Return
A number of past villains in the Marvel Cinematic Universe have a very specific thing in common - their demises all came at the mercy of, or while wielding one of, the powerful Infinity Stones. The aforementioned Red Skull was either transported to the other side of the universe or killed by the Tesseract (likely to be the former), Malekith was killed by his own ship while trying to use the Aether to restore the Dark Elves' dominance, Ronan was killed when the Guardians of the Galaxy unleashed the power of the Orb on him and the last Ultron drone was destroyed by a blast from the Mind Gem. With that in mind, one fan theory suggests that Thanos will effortlessly be able to resurrect them when he's wielding said stones, due to the fact that their essence is held within them - and the idea of Thanos having an army of supervillains at his mercy, in addition to wielding the Infinity Stones, is a truly exciting and deadly one.