This week we get introduced to the villain of the story as Tom Welling and Michael Rosenbaum revisit Smallville Season 4 Episode 17: ONYX! Michael takes us behind the scenes into his process for giving Lex an evil arch in this episode, sharing how he went above and beyond evil in certain scenes. We also find where the mask has been hiding all these years and even get a ‘Damn Who’s That’ moment in this episode.