@ darth: chapter 9 boss was pretty enjoyable imo:
i had 1 Healer, 1 Defender, and Lightning as Breaker (? this red written class).
i have fought for a LONG time, but i made it with that. i first killed the heads with lightning, (maybe you can switch the defender in your group to this blue written Damage class to increase the output), and then the big guy came. had no problems at all, just bad luck @ my first try, because my group was very close to each other, and all got hit <.<
if u receive too much damage, you can switch lightning from Damage to healing too, but i dunno if i did that.
(you could also increase your defense with hope's magic.)