kamicrazy2112

Best answer as chosen by Asker / Ratings
The best technique is to use three warriors - all three having learnt one Break attack. Have one of the girls using Power Break, another using Magic Break, and the third using either Armour Break or Mental Break (depending on whether you plan to attack it physically or magically). Once you get it's attacks really low (say, around 30 HP per attack), switch dresspheres to the most powerful one you own and just attack him. If you use the mentioned technique, you should kill it off in no time since you are lowering it's attack power, magic attack power, and it's defense.

Tip: helps if you're around level 45+...