<Li> Stellan Skarsgård as Erik Selvig: Foster's mentor and colleague . Skarsgård said, the film finds Selvig in a "disrupted mode" explaining, "Having a god in your head for a while creates some psychological problems", referring to the character's ordeal following The Avengers . </Li> <Li> Idris Elba as Heimdall: The all - seeing, all - hearing Asgardian sentry of the Bifröst Bridge, based on the mythological deity of the same name . Elba said he has a larger role in the sequel, "In the new film we're going to get to know Heimdall the Asgardian a bit better, and we're going to get to know Asgard a bit better . I can't say too much, but the expansion of Thor in his world is going to be huge . My part was very small and functional in the first film". </Li> <Li> Christopher Eccleston as Malekith: The ruler of the Dark Elves of Svartalfheim . About Malekith's motivation, Eccleston said, "There is a kind of tragic quality to his quest . Because he's lost his wife, he's lost his children . He's lost everything . And he returns for revenge . And the agent for his revenge is the Aether . If he gets hold of that, he is omnipotent ." Eccleston continued, "What I thought about a great deal was revenge--there's huge amounts of revenge . One quote is:' When you seek revenge, be sure to dig two graves .' I did a film called Revengers Tragedy where I played a guy called Vindici--from the word' vindictive'--and he is the distillation of revenge . So, in a way, that was what I had to think of: how revenge can make you absolutely monomaniacal--though you're still trying to make it recognizably motive - led . It's just the personification of movie evil ." However Taylor stated that a lot of scenes involving Malekith's backstory had to be cut from the film to make it more efficient . Eccleston revealed that he speaks an invented language for the film explaining, "The Elvish language is definitely based on European languages . I think there's probably some Finnish in there . It does have its logic and its rhythms . It also has many syllables and it's very difficult to do while remaining naturalistic . It's been a particular challenge for us but hopefully it gives the film some complexity and variety ." Eccleston also said the role required six hours of make - up and 45 minutes in wardrobe . </Li> <Li> Adewale Akinnuoye - Agbaje as Algrim / Kurse: A Dark Elf, and Malekith's trusted and loyal lieutenant, who is transformed into a monstrous creature in order to destroy Thor . Akinnuoye - Agbaje described Kurse as "an amalgamation of a bull and a lava - like creature . He has very animalistic tendencies but with this insatiable and unstoppable power . As an actor, that's one of the hardest things to embody . You have to realize you are probably the most powerful thing you could imagine . And you have to be that . You can't pretend, so that when you face Thor, it's real ." Akinnuoye - Agbaje stated the role required three hours of make - up a day and had to put on heavy duty prosthetics explaining, "The outfit weighed about 40 pounds . I'm sure there will be a certain amount of CGI but a good 80% was me in that suit ." About the character Akinnuoye - Agbaje said, "I suppose Algrim and Kurse would be the quintessential baddies, but in reality they are what I perceive as the scorn and the victims of the story . They are the elves who have basically lost their planet and their race to another race, the Asgardians . Here is a man / alien who places a noble objective beyond his own life and I think there is something extremely inspiring about that because he looks at the bigger picture and sees himself as a means to that end ." Akinnuoye - Agbaje added, "I worked with director Alan Taylor in trying to maintain Algrim's humanity all the way throughout Kurse's transformation, so that even when you see Kurse the beast, you can still relate to him as being Algrim inside . And symbolically we did that by keeping the same piercing blue eyes throughout ." </Li>

Who plays malekith in thor the dark world