Lunar Titan is an optional boss in the Advance and Complete Collection versions of Final Fantasy IV. It is fought during Yang's Lunar Trial at the Lunar Ruins. When beaten, the player obtains the Martial Armlet, which changes Yang's Focus command to Deadly, and the Grimoire LT which, if used as an item, summons Lunar Titan to deal 9,999 damage to all ground enemies. Using up the Grimoire unlocks the trial door again.