4. Dr. Maya Hansen
As the co-creator of the Extremis virus previously mentioned in this list, Dr. Maya Hansen remains a curiously interesting character. And who better to play her than the genuinely talented and lovely Rebecca Hall? The English actress signed on to play the character "because I've never done the 'hurry up and wait' movie before. Even the studio movies I've done have been small studio movies, or indie films that we made on a wing and a prayer. I love those, but
Iron Man is refreshing." In the comics, Maya enlists Tony Stark to help her recover the stolen Extremis virus after Killian lets it loose to a bunch of terrorists. Eventually this culminates in a team-up between the scientist and the Stark man, presumably one that will also take its place within the confines of
Iron Man 3: let's just say Tony Stark is interested in the capabilities that Extremis might bring him, and that Maya isn't quite all that she seems.