Problem with Kefka normal is that is whole difficulty relies on not knowing what he is doing. Once you explain him he is trivial, way more than exdeath was. But he will wipe people if not explained. The third boss for some weird reason is much harder than him, because he uses more and faster mechanics despite being able to see and understand his mechanics plainly.

So its more of an issue to spoil him. He's either one-shottable, or he will wipe the newbies often otherwise.