Tom Hiddleston is my headcanon for Erik. Yes, I know he's extremely handsome, but I think he'd definitely be game for sporting a good deformity, and he plays the psychotic yet sympathetic antihero so well that it seems like the role would be a natural fit. He would be terrifying yet pitiable.
"I had to find his smile, his innate love of anarchy and chaos. I had to make his pain real. Great villains are born from tragic circumstances. They become dangerous when their vulnerability hardens into vengeance." [Tom Hiddleston on Loki]. Source: http://www.tv3.ie/xpose/article/entertainment-news/171076/Tom-Hiddleston-lucky-to-play-Loki