As I've touched upon in recent articles, the villains that have appeared in the Marvel Cinematic Universe so far have failed to really make me believe that the heroes have ever been in any real danger. That's likely to change somewhat with the likes of Ultron, Malekith the Accursed and, eventually, Thanos in the pipeline - but which other villains could cause a real mess in the MCU? I've been giving that some thought and, without just throwing any old powerful villain in to the mix, I've thought of some who have history with the current (and inevitable) crop of Marvel Cinematic Universe heroes and would make for incredibly interesting on-screen storylines and could potentially threaten every single hero - or even potentially threaten the entire universe, based on their showings in the Marvel comic book stories that have involved them. With that in mind, here are ten powerful villains who would really tear up the Marvel Cinematic Universe...
Honourable Mention: Galactus
Sadly, this is very unlikely to ever happen, hence his exclusion from the main list, but Galactus would really pose a treat to the heroes of the Marvel Cinematic Universe. It's also debatable as to whether or not Galactus should really be considered a villain. He is really just a neutral cosmic entity whose existence is essential for the balance of the universe and he only does what he does (devours planets) as a means to live - he is no more a villain, therefore, than us humans are for eating meat and, indeed, we are no more relevant to him than ants are to us. However, he has come in to conflict with the likes of the Avengers in the comic books and they have been forced to fend him off, alongside the likes of the Fantastic Four, when he has attempted to devour Earth. That said, he has also fought alongside them as well. He would be a great addition to the MCU but, as already mentioned, it's very unlikely to happen because Fox Studios have the rights to him, having acquired them for his dismal appearance in the Fantastic Four movie, the Rise of the Silver Surfer. On to the actual list...