It makes it a much more interesting fight than superbosses where you just have to repeat one strategy over and over or who use the same attack pattern over and over, IMHO. Ozma at least provides variety. With most other super bosses (mind you, not all of them), if you have the right setup, the outcome is always pretty much guaranteed. Similar to Yiazmat, that's not challenging in the slightest; it's simply a grind until you're capable of using that strategy with that gear. With Ozma it is not and I like that. There's nothing wrong with a bit of luck being needed to win.