Mammon uses the same abilities and attack patterns during both of her boss battles. During the beginning of the battle, Mammon uses normal physical attacks and the Diamond Dust ability. Mammon is able to use some positive and negative status spells. As the battle progresses, Mammon begins to use Blizzard Dance, which inflicts moderate water-elemental damage to all members of the opposing party. Mammon opens the battle with three arms, allowing her to act four times per turn during the beginning of the battle. Mammon loses an arm when her HP is depleted by fifteen percent. When all three of her arms are gone, Mammon drops to the ground and acts twice per turn.
Players are highly advised to equip an Ice Shield and a Confuse Cape to all party members. Since Mammon is weak to fire, the player should equip fire-elemental spells and weapons. The player should also have Esuna in their inventory, since Mammon may inflict Confuse and poison on the party.
Since Mammon uses the ice element, an Elementalist is very useful to mitigate Mammon's damage output and buff the party's fire element. If the player has Lux, they should cast it at the start of the battle. The player should also have two damage-dealers (Black Mage, Hero, and Fighter are good choices, for a few examples) and one character dedicated to healing as a White Mage or a Salve-Maker. An Alchemist is the best damage dealer for this fight if it is available. When Mammon has arms, she will always cast Protect and Shell. Bomb Fragments, purchasable from Liberte, ignore Defense and Magic Defense and deal double damage when used by Alchemists.
The Elementalist should use Mysterio and recast it whenever it wears off. The damage-dealers should pound away steadily to destroy Mammon's arms; if the healer has time between healing, he or she can use Poison Pill or attacks to help. Mammom will start to cast Confuse on single targets, so use Esuna or a Remedy. If the party's HP starts to fall, take the time to heal. The two damage-dealers should continue their attacks until Mammon is defeated.