Sky (天空, Tenkū?) is a recurring battle location and terrain type in the Final Fantasy series. Most of the time, battles takes place high up in the sky, usually standing on the deck of an airship fighting an aerial enemy. These battles are in most cases one time only encounters, but in some games the player can engage random encounters while flying across the skies.
The player can engage enemies while flying their airship in the sky, while piloting the Invincible. Battles on board the airship begin with a volley of cannonfire at all enemies. A Geomancer that uses Terrain during these battles will use Tornado to deal Wind-elemental damage to all enemies.
The first sky battle occurs when the party tries to leave Vector and they are attacked by two Cranes. Later, they engage in a few battles while trying to reach the Floating Continent, and the party is later knocked off from their airship by Typhon. While falling from the sky, the Air Force attacks them. The optional battle against Deathgaze in the World of Ruin also takes place on the deck of the Falcon. Furthermore, the final battle against Kefka is fought far up into the clouds.
Ultimate Weapon second encounter takes places in the sky, and the party will fight it while on the deck of their airship, the Highwind. The player will need to ram it in the sky to engage into an aerial battle against it.
Evrae appears before the Fahrenheit while the airship heads towards Bevelle, the party fights it on the deck of the airship. Other battles includes Left Fin, Right Fin, and Sin. In the International/HD remaster versions, the superboss Penance can be fought on the airship's deck after defeating every Dark Aeon.
The primal Bismarck is fought on a floating rock being towed by the airship Enterprise, in the trial "The Limitless Blue."
There's a terrain tile called Sky, but there is no Geomancy ability associated with this tile and units cannot walk or stand on it. The map is called Eagrose Castle Solar and it does not appear within normal gameplay, it only appears within a cutscene. The only way to see this tile is by using a hacking device to battle inside the office map and then rotating the map. The terrain tile "Sky" appears only on this map at the two edges.
Like Final Fantasy III, the player can encounter enemies while flying across the skies. Talon will detected the enemy and it will attack with its primary weapon which will depend on what the player set it to be. The surviving enemies with board the ship engaging the party into a battle.