The trailer for Avengers: Age of Ultron was leaked a week before it was supposed to premiere, and by now weve all had a chance to get our expectations built up for the return of Earths Mightiest Heroes to the big screen. One thing weve known for a while is this is the introduction of several new characters into the Marvel Cinematic Universe. First, theres obviously Ultron, the robotic villain of the film. Then there are the superhuman twins, Quicksilver and the Scarlet Witch. Also Baron Wolfgang Von Strucker, who as we saw in the post-credits sequence of Captain America: The Winter Soldier, is somewhat involved with Hydra and conducting experiments on Lokis staff from the first film. Weve also got Paul Bettany, who previously provided the voice for JARVIS, the artificial intelligence that helps Tony Stark run his Iron Man armor and his house. Bettany is getting an upgrade as JARVIS gets a body and becomes the Avenger known as the Vision. But who are all these new characters? What are some things about them from the comics that might give us some clues as to their roles in this film? Here are ten things that youll probably want to know about the new characters before the film premieres next summer.