The notion of a film of the Justice League of America is generating a lot of excitement, so I thought Id think about one important factor of this film, if it arrives at the cinema. What villains are so dangerous and powerful that not even Superman can stop them on his own? (Just having a lump of Kryptonite on them, is not going to cut it.) So in this article Ive tried to think of enemies that would pose a threat to Superman, Batman, Wonder Woman and the Flash. Those are the four most likely to be in the script as a given. Green Lantern may have too many bad memories attached to him. The Martian Manhunter could be removed as Hollywood might believe after John Carter that anything referring to Mars is a kiss of death. As Green Arrow is getting his own TV series, they may not want him in the film, to avoid confusion. So they may well go and find other characters to fill out the ranks. Anyway, who could challenge the super-friends?