Sky Fortress Bahamut The Sky Fortress " Bahamut " is a massive airship in Ivalice , the world of " Final Fantasy XII " . Designed by Doctor Cid to be Archadia ' s ultimate airship , the structure is so large that normal power supplies are insufficient to fuel it . It serves as the game ' s final dungeon . Similar to the Great Crystal in Giruvegan , the map shows a sketch of the Sky Fortress rather than a real map , with an approximation of the player ' s location . Hovering over Rabanastre , the " Bahamut " can only be reached by the " Strahl " . Once entered , the party cannot leave and there also are no Save Crystals . Structure . The " Bahamut " serves as a capital ship , aircraft carrier , and superweapon for the Archadian armies . It carries a large complement of fighters and has rapid - firing cannons placed on the hull , and utilizes a multitude of glossair rings to support its massive structure . It is so large it is capable of generating a whirlwind when flying . Its most prominent feature is the Cannon Superstructure placed near the top , a powerful cannon powered by Mist that can destroy enemy airships with a single blast . Armaments . The " Bahamut " weaponry are deadly enough to take out an airship armada . Its mist cannon fires a large amount of Sun - Cryst ' s energy to destroy an airship in a single blast , causing it to explode into Mist . However , it takes a long time to recharge . The cannon beam itself is fast , making any heavy airship , such as carrier and frigate , unable to avoid it . The " Bahamut " also has anti air guns surrounding its body that are possibly operated both manually and automatically . Some are seen operated manually by the imperial pilots . Story . The " Bahamut " is the Archadian Fleet ' s flagship involved with crushing the Resistance . It can only fly when a large quantity of mist is supplied . Such energy is obtained once Reddas destroys the Sun - Cryst , allowing Vayne Solidor to pilot the craft into battle with the Resistance over Rabanastre . Though the two fleets were otherwise a match for each other , the " Bahamut " turns the tide and decimates the Resistance airships . Ashe ' s party , piloting the " Strahl " , docks at the " Bahamut " , and Ashe and her allies lead a force up the airship to find Vayne . Along the way , Judge Gabranth arrives , driven to kill his twin brother Basch . The Judge Magister is defeated , but Basch spares him . On the Bahamut ' s bridge , Vayne greets the party with is younger brother Larsa , who turns on Vayne as he opposes the war . The party apparently kills Vayne , but he rises again as Vayne Novus using the power of manufacted nethicite . Gabranth stumbles to the scene and assists the party in battling Vayne to ensure Larsa ' s safety . After a fierce battle , Gabranth attacks Vayne but is struck down . Vaan picks up Gabranth ' s fallen sword and impales Vayne , forcing him to retreat to the top of the " Bahamut ' s " cannon while Vayne ' s Occuria n ally Venat momentarily prevents the party from following . Having achieved its goal , Venat breaks up into wisps of energy that bestow a dying Vayne the power of an Occuria , grafting pieces of the " Bahamut " unto himself to become The Undying , a mechanical monstrosity . When The Undying is destroyed , the party flees to the " Strahl " as the " Bahamut " begins to descend on a crash course with Rabanastre below . Balthier and Fran stay behind to repair its glossair rings and the " Bahamut " crashes just outside the city . A year later it has been covered with plant life , and a small lake surrounds the base . Other appearances . " Dissidia 012 Final Fantasy " . The Sky Fortress ' s Cannon Superstructure area , where the party fights The Undying , appears as an arena . It is here that Vaan witnesses Kefka arguing with Terra and torturing her when she refuses to fight , and Vaan eventually battles Kefka and flees with Terra . Kain begins his storyline here . Lightning is also briefly fought alongside the Warrior of Light against Kefka and Ultimecia . The stage consists mostly of a large bridge over a Banish Trap with several breakable pillars , leading to a circular central area with a small sloping rectangular area . The doorway to the inside can be seen on the other end of the bridge . Grind bars ringing the outside of the stage lead from the end of the rectangular arena to the other end . In the Omega version the sky glows orange with Mist as the fortress speeds forward , the wind blowing characters back towards the edge of the arena when dodging or jumping — characters move normally when attacking in the air , including chase sequences . Characters hit by wind lose a percentage of their Bravery , which is added to the Bravery Pool as though they were caught in a Banish Trap . The far end of the stage becomes a Banish Trap that teleports the characters back to the central area , which characters can be blown into if they are in the air long enough . The Bravery Pool rises quickly when both characters are on the ground , and rises at a slower pace when only one character is on the ground — it does not increase at all when both are in the air . The Sephira is the battlegen item obtained through stage destruction in this area . " Dissidia Final Fantasy " ( 2015 ) . Sky Fortress " Bahamut " appears on the background of the Rabanastre level during its transformed state alongside various other Archadian airships . It alludes to the battle above Rabanastre at the end of " Final Fantasy XII " . " Theatrhythm Final Fantasy " . The Sky Fortress " Bahamut " appears as the Battle Music Sequence for " Boss Battle " , " Desperate Fight " , " Battle for Freedom " and " Ending Movie " , the latter appearing during a Dark Note only . " Theatrhythm Final Fantasy Curtain Call " . The Sky Fortress " Bahamut " returns as the BMS for " Desperate Fight " , " Battle for Freedom " , and " Ending Movie " . Musical themes . " The Sky Fortress Bahamut " is a location theme from " Final Fantasy XII " . It is written by Hitoshi Sakimoto and is the fourteenth track on disc 4 of the . It plays as soon as the player enters the " Bahamut " . The track starts off with percussion and violin before giving away to a militaristic march . A rendition of " The Sky Fortress Bahamut " appears in " " as " Finale / The End " . It is the nineteenth track of disc 2 of the , also written by Hitoshi Sakimoto . Etymology . The main ships of the Archadian fleet are named after recurring summoned monsters from the " Final Fantasy " series . Bahamut is usually a top - tier summon , reflected in the " Sky Fortress ' s " status as the Empire ' s ultimate airship .