When cast, Guardian creates an image of a golden shield with wings over a single ally, buffing their Defence, Magic Defence, and Evade. It essentially combines Protect, Barrier, and Reflex, but targets only a single ally instead of the entire team. It is particularly useful in re-buffing allies who lost their buffs due to their death, dispel, or simply were in the backup slot.
Epic Battle Fantasy 3
Guardian is unlocked by completing a quest in Glacier Valley for Celeste, it can be learned by any of three available characters. Other than buffing an ally's stats, Guardian also slightly heals the target.
Epic Battle Fantasy 4
Guardian can be learnt by Matt, Natalie, or Anna, but is no longer available for Lance. It is stronger than its EBF3 appearance, but it doesn't heal the target any more. It is found in a chest in the Temple of Godcat, in front of the third Blood Orb gate.