I easily remember this battle being one of the hardest in the game. The marionette they speak of?

33 health, 99 magic points, the ability to cast LEVEL 4 FREEZE, and a level of an unknown number, when my best attacker can only do a little damage and the average level of my army is 5-7 and my healers have terrible hp and def stats. -.-

Did I mention there's no out-of-story grinding?