The thing is, the only thing you've really done was just continue to spam "Sephy is the best and I hardly have any proof for my claims" for the past few pages. You probably wouldn't like it if I posted "kefka is awesome" over and over again either. Also, people that are actually trying to debate here are posting proofs and reasons for why they think that way and not just their opinions. If you really were 'just wondering' what we all thought, you wouldn't be spamming "Sephy is the best" over and over again. I don't really care that you think Sephy is the best, but just try and give detailed explainations and proofs of why. Expressing your opinion is fine, but everyone else here gives reasons and proofs why they think that way in their posts, something you apparently can't do.
I'd probably be more insulted if you didn't just agree with yourself a few pages ago.
On Topic:
Kefka does have more power than Sephiroth, but I doubt Kefka could survive ten slahes in one second by Sephy (KHII). Kefka is stronger is terms of magic, but Sephy is faster and physically stronger.