Despite the implications of his name, Ras al Ghul was the weakest big bad of Arrow so far. All of the mystical shenanigans were so nonsensical that he really ceased to be intimidating shortly after he skewered Oliver. The skewering itself remains seriously scary, but it says something about a villain that his best moment came nine episodes into a twenty-three episode season. It didnt help that Matt Nable didnt look like he could beat Stephen Amell in much more than a thumb war. Luckily, the new-to-Season 3 big bad Damien Darhk has been fabulous. Neal McDonough is no more physically imposing than Matt Nable, but his icy blue eyes combined with Darhks magic ranks him as Oliver's most formidable enemy since Season 2. Best of all, hes been unfailingly evil. Whether he was gloating over crippling Felicity or killing henchmen who displeased him or kidnapping Olivers kid, Darhk never failed to bring the evil. Theres no saying where hell go now that hes lost his magic, but hopefully hell find non-magical ways to terrify.