Well, I'd say that Seymour wasn't really the main villian but he was deff. a villian trying to get more power by trying to get to sin... And eventually if he did, that would be pretty bad. It's kindof hard for me. idk, because if i'm correct, we see/hear from him the most. Yunalessca and all them other people we don't hear about see them as often until towards the end of the game. I don't exactly remember haven't played X recently so correct me if i'm wrong XD Seymour did have the Guado's in the palm of his hand pretty much... But, like others said it could've been Yu yevon thats the main villian.. I should play that game soon and retouch up to that XD