Oh no, it's not that she appeared suddenly that bothered me. I can handle that, although I still don't like it because I feel the best villains are ones that have time to establish themselves. What bothered me about her is that her motives just didn't make sense. She was just doing it for the evulz, if you will. I can swallow some ultimate force of darkness who wants to destroy to the sake of it as an rpg end boss, but Ultimecia was supposed to be somewhat humanized, and as such I expected her goals to have some meaning to them.