Achieved by AH or by completing the San d'Orian Quest "The General's Secret" started by Curilla in Chateau d'Oraguille. You must have San d'Orian Fame 2 minimum to activate the quest, and if San d'Orian, must be past Rank Mission 1-3, if not San d'Orian must be past Rank Mission 2-3.
NPCs for about 1,440 - 1,476 gil.
