It's kind of weird (and maybe lame?) but the only characters I could really see winning this tournament are Otohime, Luffy and Usopp. If you just think about it it's not very likely that someone like let's say Franky-san could have a potential chance to win it or to even make it to the finals. After all everything's based on recent events (i.e. Otohime and maybe Fisher Tiger) or being a main character.
But well... may it be a great second round nonetheless.