- “I just needed to borrow the power from wretched souls that can't die... Where did I acquire it? It was the Invincible, or should I say, that large eyeball in the sky?”
- “Battleship... Invincible... prototype... Prototype... failure...”
- —Hologram at Oeilvert
According to ancient Terran recordings at the ruins of Oeilvert, the Invincible was developed many times in order to refine it into a perfect tool of war. The final version was entrusted to Garland, who recognized its potential as a weapon of destruction. The Invincible's underside contains a large, crimson "eye" that has the ability to fire a devastating energy beam and enslave eidolons.
It is also revealed that the Invincible hosts numerous souls trapped within it, apparently absorbing them in events such as the Battle of the Iifa Tree, although the exact meaning of this is never explained. The Invincible is Garland's method of traveling between the two worlds of Gaia and Terra. The reason Kuja is never seen on-board the Invincible, even though he appears to work with it during the storyline, is probably because, according to the Final Fantasy IX Ultimania, Garland has banished Kuja from traveling between the worlds.
The signs of the Invincible's power are first seen in the game's opening FMV, where a young Garnet and her mother are seen sailing away from the burning village of Madain Sari in a boat. Garland attacked the city with the Invincible in fear of the resident summoners' ability to call forth eidolons, a talent that could hamper Garland's plans to assimilate the world of Gaia into Terra.
Over the course of the storyline, the Invincible is used twice more. Kuja, having gained control of the ship, uses it to possess Bahamut at the shores of the Iifa Tree and commands the eidolon to kill Queen Brahne. Princess Garnet attains Alexandria's throne, though her coronation ceremony is halted by tragedy. Kuja, relishing his new powers, sends Bahamut on a rampage through Alexandria, but the dragon's flames are quelled by the eidolon Alexander Garnet and Eiko Carol summon together. Though Bahamut is vanquished, Kuja attempts to enslave Alexander instead. This fails, as Garland, fed up with Kuja's insolence, appears on the decks of the Invincible and uses it to destroy Alexander.
The airship does not appear again until the player's party ventures to Terra and spies the Invincible levitating above the entrance to Bran Bal. Garnet faints upon seeing the ship, realizing the Invincible was the machine that deprived her of her hometown. The heroes confront Garland within Pandemonium, but Kuja, having arrived to Terra on a Silver Dragon, steals the Invincible and, being a Genome, absorbs the souls residing within the ship into his body to achieve Trance.
After Kuja murders Garland; Zidane and his friends, along with the Genomes, take control of the Invincible and pilot it back to Gaia. They never fall to the temptation of using the ship for destructive purposes, instead flying it into Memoria. What happens to the Invincible after Necron is vanquished is a mystery, as it is never seen again after the party returns from the Crystal World.
Location: Gilgamesh in Daguerreo, Card Phantoms in Memoria, Chocobo Treasure at the Shimmering Island's ruins on disc 4.
- The Invincible resembles Yoshitaka Amano's conceptual artwork of the airship, Enterprise, from Final Fantasy IV. Its concept, however, as an airship able to travel between worlds, seems based on the Lunar Whale, also from Final Fantasy IV.
- The Stellazzio coin, Pisces, can be found on the airship's deck.
- The Invincible has the same name as various airships from previous Final Fantasy games (the first Invincible appeared in Final Fantasy III), but looks nothing like any of the airships that share its name.
- The Invincible shares a similar color pattern to Exdeath's armor in Final Fantasy V.
- The Invincible possessing an "eye" on its underside is a recurring design trait in structures built using Terran technology.