Malekith along with the Dark Elves from last years Thor the Dark Elves from Thor the Dark World make their appearance in Hulk and the Agents of Smash and since the episode "For Asgard" airred 4 months away from the film's realease in November, Malekith and the Dark Elves now hold the record for appearing in the cartoons in MCU versions since seen in the Marvel Cinematic films.
What is also interesting about Malekith is that in this version he is depicted in his Thor the Dark World version while retaining his iconic color scheme from the comics.
And around the end of the episode, he morphs his head into the shape of what he looks like in the real world's mythology which is really demonically intimidating
the only thing disappointing about Malekith in this show is his voice sounding less like Christopher Eccleston and more wimpy toned as he was revealed in the end cast credits to have been voiced by James C Mathis III with the same accent that he used to voice King Cobra in The Avengers Earth's Mightiest Heroes. Technically the voice over for this episode was done before the first Thor sequel trailer's release so if Malekith appears in Ultimate Spider-Man season 3 and Avengers Assemble season 2, the casting director of those shows will be sure to have someone with a voice similar to Christopher Eccleston's do the voice for the character otherwise that person is just as screwed as the one in charge of the voice casting in Hulk and the Agents of SMASH.