They could fight well even though they lacked experience, but they could still overcome this fight as best they could. Several times their HP decreased, several times continued to use HP and MP Potions, but they didn't give up against that BOSS Sakata Sakamoto. Don't attack, only know the word spirit, that's what maybe I can see from their personality.
Ferdinand did his job so well, protecting his party members. He has the most vital task, otherwise, they wouldn't have come this far. Nathan is also good at playing his weapons and skills, he is like Rifai who is playing this game for the first time. Even though Pian is still clumsy, he can still act and is assisted by his friends. Nindy is also quite proficient with her rapier, maybe she really likes to stab. I hope in real life, she's not like that.