I keep training after I get the airship, Monster Arena is the perfect choice, TRAIN AND TRAIN AND TRAIN AND TRAIN, here I am, beat that Nemmy easily.
The hardest choice is the greatest result: That always live with me.
I hope you know that this is the first Seymour duel, not the last, so the Arena is not yet an option for several hours of play. Also Yuna is not with the party.