"win the duel in 3 turns"
While having the dumb Shark AI as your tag partner.
Yeah, right. Konami never tested it (to see if it was even possible to win in 3 turns) or something?
Yeah right. The first time I summoned it, Shark dealt the finishing blow with his own Bahamut Shark instead.
It's not until like, 6 duels later against Scorch and Chill that I finally managed to get a situation where I (instead of Shark) gets to deal the finishing blow, which means I get to do it using my Black Ray Lancer.