Its basically an easy battle even in high difficulty mode as long as you know how to equipped your character.
Exactly, but not everybody knows how to properly train and equip their character.
For an instance, the first time I did the finally battle, I was a Warrior who didn't have any of the Warrior skills. I had the Healing Ghost maxed, the Dual Wield maxed and a lot of other Dragon Knighs skills. If only I had known better, that fight would've been really easy!
With a powerful mage it's cake.
