The Ultima Weapon is a biotechnological weapon from Final Fantasy XIV. Appearing during the events of the initial A Realm Reborn main scenario questline, the Ultima Weapon is a massive Allagan war machine that is being used by the Garlean Legatus Gaius van Baelsar in his plan to overtake Eorzea.
Since its initial appearance, more difficult versions of the Ultima Weapon have made later appearances as Minstrel's Ballad content, with "The Minstrel's Ballad: Ultima's Bane" in Patch 2.1 and a new high-end difficulty raid in Patch 4.3 known as "The Minstrel's Ballad: The Weapon's Refrain".
It is a relic of ancient Allag, excavated from its resting place deep beneath Ala Mhigo. The Allagans used it to crush primal and foe alike...and now the Garleans mean to do the same!
The Ultima Weapon is a biotechnological, anti-primal war machine created by the Allagan civilization ages ago that was placed in stasis deep beneath what would later become Ala Mhigo. However, after the Seventh Umbral Era, the Ultima Weapon was found by the Garlean Empire and entrusted to Gaius Van Baelsar, who restored by having it absorb the primals Ifrit, Titan, and Garuda to assimilate their abilities. With this, he intended to use it to intimidate the city-states of Eorzea and the beast tribes.
Rejecting the terms of the ultimatum, the city-states instead reinstated the Alliance and launched Operation Archon to strike against Gaius's XIVth Legion and eliminate the Ultima Weapon itself at the Praetorium. Van Baelsar piloted the warmachine himself in the final battle, but despite his efforts the Light of the Mothercrystal shielded the party. As the Ultima Weapon took damage, the absorbed Primals were gradually released.
As Gaius became frustrated with the apparent strength of his opponents, Lahabrea appeared and explained the only way to break the shield of Light is to bring down the hammer of Darkness. He then revealed the core of the Ultima Weapon, the Heart of Sabik, held a power that lain dormant for eons: Ultima. Lahabrea activated Ultima, devastating the Praetorium and draining Hydaelyn of the means to shield the Adventurer. Despite being on more even terms, the party managed to destroy the Ultima Weapon before Ultima could be cast again. As it disintegrated, Gaius ejected from the failing war machine.
Following the defeat of the Ultima Weapon the Wandering Minstrel is encountered in Revenant's Toll and asks the Adventurer to recount their battle with the Ultima Weapon in order to make a song about the climax of the battle in The Prateorium. Through his song the Adventure finds themselves re-living their encounter with the Ultima Weapon, but can't help but notice that the Wandering Minstrel took liberties with the story and the battle is much fiercer than they originally remember.
The Ultima Weapon is fought during the second and third stages of the final battle, piloted by Gaius. In the first fight, it has access to several primal abilities, including their respective signature attacks, but once enough damage is done, each primal is forced out of it. Ultima Weapon gains new abilities for the third battle, including the Ultima spell. If Ultima is successfully cast in battle, it's an instant loss.
Patch 2.1 launched with a Hard Mode variant of the battle with the Ultima Weapon. Emerging victorious from this battle will yield item level 80 accessories. In addition, it has a chance of dropping a Faded Copy of The Maker's Ruin. Since the inclusion of the unsync function in duty finder with the initial launch of the Heavensward expansion, the original challenge of the fight has been severely reduced, with players often defeating the boss in less than 30 seconds.
The Ultima Weapon has 2 battle themes, one for each phase of battle. Both themes were composed by Masayoshi Soken.
The theme played during the first fight is called "The Maker's Ruin", the song contains a Latin chorus chanting.
The second part of the fight is fought to the song "Ultima". The theme is used again in the battle with the superboss version of the Ultima Weapon in the sidequest "Minstrel's Ballad".
Similar to "The Maker's Ruin", this theme contains a Latin chorus chanting. The chanting in this song was randomly generated and as such there are no official lyrics. 
Ultima Weapon appears as a boss.
The Ultima Weapon appears as an event-exclusive boss. This boss is only available in high-difficulty quests of Ring of Braves multiplayer region for limited-time as a part of Final Fantasy XIV collaboration:
- The Ultima Weapon of the Magi (Difficulty: ★3)
- The Ultima Weapon of Darkness (Difficulty: ★4)
- The Ultima Weapon of the Phantasm (Difficulty: ★5)
His appearance is based on his original appearance in Final Fantasy XIV: A Realm Reborn.
Ultima Weapon from Final Fantasy XIV has a Triple Triad card.
Ultima means "the last" in Latin and many Latin-based languages. In the Spanish versions of many Final Fantasy games, it is written as "Artema," a close transliteration of the Japanese katakana.