I've never beat Ozma because I don't really care that much about beating it. I've heard Ozma can be relatively easy or hard to beat just because of random factors in the battle that you can't really prepare for. So the battle could be a pain even with a guide, or you could be lucky and just win first try. I can't remember for sure if that's the boss I'm thinking of though. VIII and X-2 were the only games I really messed with super bosses.