I beat the final boss with a Minstrel, Priest, Warrior, and Martial Artist. Lots of attack power + multiheal gets the job done.
To level up fast go to the Bowhole. Get to the final stairway that leads to the boss room, and stand in the topright corner of the little platform it's located on and sit tight while watching the enemies spawn and walk by. When you see a Liquid Metal Slime, pounce on him and finish him of as quickly as possible (if your party's over level 40 then they tend to run away often). Those things will give you tons of XP. I had to grind a Priest up for Multiheal and got her to level 38 this way.


