Vivi learns some incredibly powerful magical attacks, but because his physical strikes are so weak, he depends on spell-casting to an extreme. Thus, Vivi’s abilities are practically negated if the enemy casts a Reflect spell. To counter this, a White Mage (like Dagger or Eiko) must cast Reflect on herself, and then Vivi can bounce spells off of her at the enemy.

Arguably, Vivi’s most powerful spell is the Doomsday spell, which inflicts Shadow damage upon everything on-screen. Prepare your party accordingly when Doomsday is cast, and learn how to use it effectively against enemies. Your party must be equipped with armor and accessories that nullify or absorb Shadow damage; otherwise, the spell will inflict massive damage on everyone. To use Doomsday most effectively, have Vivi and Steiner collaborate to cast Doomsday Sword, which enables Steiner to focus Vivi's magic onto a single enemy instead of everyone.