Board Thread:Questions and Answers/@comment-124.240.187.87-20150724111647/@comment-28600204-20150724164621

If I HAD to say one I'd say the Night's King but to be honest like Dragon said it doesn't really work like that, the story has multiple major antagonists like Joffrey Baratheon, Roose Bolton, Ramsay Bolton, Littlefinger and Cersei Lannister and they're focused on more than a proper main antagonist.