Lucifer uses the same abilities and attack patterns during both of his boss battles. Lucifer is able to use wind and light-elemental spells. After three turns, Lucifer flies into the air and begins to use Judgment Bolt, which reduces the AP of all members of the opposing party to zero.
The player should have some Animate Tonics and Esuna in their inventory, since Thundara and Thundaga may inflict paralysis. Players are highly advised to equip a Holy Shield and dark-elemental spells and weapons. As with the other demons, an Elementalist is very useful in mitigating the damage for Lucifer's attacks. The player should also have either a White Mage or a Salve-Maker to heal. A Bandit may also be desirable as the Lightbringer sword can only be obtained by stealing it from Lucifer, though it can be done in either batte.
If the player has obtained it, Lux should be cast at the start, but the battle is still winnable without it. The Elementalist should use Mysterio and Amplify while the damage dealers use their own job abilities (such as Jugular, Finale, etcetera). A black mage with Darkaga can deal critical damage to Lucifer's hit points. After Lucifer begins to repeatedly cast Judgment Bolt on the party, the player should have their party use Boost to lessen damage and to replenish AP.
If the party's HP should begin to fall during this phase of the battle, the player should concentrate on healing. When Lucifer lands on the ground again, the player should use their attackers to repeatedly deal damage to Lucifer until he is defeated.