Sephiroth wins hands down. It is obvious. Sephiroth is more evil & heartless. Where as Seifer just wants to do what he is commanded to do Sephiroth acts accordingly to what he thinks & is not a 'puppet' like Seifer is because he wants to destroy the World, where as Seifer is just accompanying[sp?] someone who wants to destroy the World.

Don't know if that made much sense Anyway, Kefka wins over both.