Boss: Yuki and Taigalion
Attacks: Blow, Mighty Blow, Power Charge+
This is easy to get. Before you can get to this battle, you must get a golem. To get a golem you have to collect 4 tickets (talk to the clown the pizza guy the girl advertising the drink thats off away from everyone else, shes in front of the second pizza place that's in the area, next to the stairs. Walk that way and you should see a girl there. For the last one talk to the girl in front of the Tropical Juice Shop. ) Once you get all four and he tells you the golems, choose the one in the middle (the Battle one) and go to the tent again to fight. Once you beat the first guy you'll go against Yuki for the achievement. Beat her golem and attack her. If you dont defeat her, the battle ends after five turns, awarding you the achievement.