9. Scarlet Witch Haunts Each Avenger With Visions
While Quicksilver's strength and super speed are conventionally cool super-powers, there hasn't really been a hero in the MCU who can compete with Scarlet Witch in power terms yet. She is the key to opening up the cosmic thread of the universe, but she's also a formidable prospect in her own right. Given the flashes that were seen in the trailers of both Captain America's past and Black Widow's, it's more than reasonable to suggest that Scarlet Witch uses her ability to create visions against the Avengers to weaken them with their own nightmares. For Black Widow, that will be her dark origin, and for Cap, the missed chance of his dance with Peggy Carter. That's going to make for a compelling sequence - especially if it leads to Hulk losing the plot.