The look they opted for the Dark Elves isn't bad...
were they from
any other mythos. Unfortunately, Malekith now resembles nothing more than a LOTR elf gone bad and when you take the original character into consideration the redesign fails. I would have moved away from the jester/glam rocker look certainly but I would have kept enough elements to make him visually striking. The skin should be a pale blue-white for starters, the hair even when pulled back a lot longer and the costume should be more baroque/ornate as befits a sorcerer. The eyes on his henchmen's masks should also be elliptical. That would make them look more alien and menacing like so:
