There's more than one strategy. I defeated them recently using this technique: -Focus on M.Defense: Equip all the star pendants you have. If you have less than 4, like me, then equip barrier shrouds and dark charms. -Have a powerful white mage (WM lv.4), and at least one medium powered white/red (WM lv.#3). The powerful white mage has to have great healing power.