I'm pretty sure he just likes Sephy.

As for Seph being a pawn, I don't recall that actually stated in the game, or I just never really realized it. Although the story would've been so much better if that were true..(C'mon, an angel Jenova as the final boss?! )

Anyway, I think that people that think Kefka is boring is probably because, well..he's the first villain to start his stereotype. So, I guess that's why he's boring. He's been overdone so much...well, that's a guess. (I suppose asking directly would be better... )

Meh. Tired..

As for worst villians, if I ever had any, I guess...well...Dark King?