Mist is a recurring phenomenon in the series usually associated with magic, and its extraction allows people to cast spells. Mist is often confused with Miasma, the poisonous substance which is seen in Final Fantasy Crystal Chronicles as a source of monsters, and in sparse locations of Final Fantasy XI as a type of impassable barrier.
Mist is but one of the manifestations of magic energy throughout the series, and can be compared to the power of elemental crystals in early Final Fantasy games, Lifestream in Compilation of Final Fantasy VII, pyreflies in Final Fantasy X and crystal energy in Fabula Nova Crystallis: Final Fantasy series.
The Four Fiends sent elemental energy in the form of four streams of colored mist from their respective shrines to the Chaos Shrine. The Warriors of Light can view this phenomenon from a viewing area onboard the Flying Fortress. The mist's power allowed Garland to travel back in time.
The Mist Cave and the Valley of Mist beyond it are shrouded in thick white mist. Cecil and Kain journey through the cave to the valley, and a Mist Dragon forms from the mist to bar their way. They later discover a Summoner in the village of Mist conjured the dragon and the mist to ward off travelers and protect the village.
In the Advance release, Rydia's trial in the Lunar Ruins involves her reverting to her child form, and her summons leaving her in a cave full of mist that obscures the player's view. After retrieving her summons and finding the cave exit, the Lunar Dragon forms from the mist and attacks.
Mist is residual element of the souls that should return to the planet, but is discharged into the atmosphere instead. According to the Final Fantasy IX Ultimania, mist appeared around 800 years before the game's start. Garland unleashed the mist upon Gaia to disrupt its people so that Terra could one day be reborn.
Mist is distributed through the Iifa Tree's roots and is in fact the Gaian souls being refused to return to their crystal and expelled to flow back into Gaia's atmosphere instead. These stagnant and tormented souls are reborn as monsters. Mist is found primarily on the Mist Continent, where its effect causes many of the kingdoms to retreat to higher elevations. The power of the mist also hardens hearts, provoking conflicts around the continent.
The people of the Mist Continent, and in particular the city of Lindblum, have developed mist-powered engines, which are primarily used to power airships. However, this means airships will only function where there is mist, meaning they can't fly outside of the Mist Continent. Additionally, the cable cars within the Aerbs Mountains are also mist-powered. Kuja taught Queen Brahne to manufacture black mages from the mist and also claims he can make Mistodons from it.
After Zidane and his party defeat the Soulcage at Iifa Tree's base, mist production stops for a time. However, after Kuja discovers his Trance powers and destroys Terra, Iifa Tree activates and Mist is expelled onto the entire world. After the Iifa Tree settles following Kuja's defeat, the world is finally freed from its scourge.
- See also: Sage Knowledge 1-26#SK 09: Mist
Mist is the source of magick in Ivalice. When densely concentrated, it becomes visible as a fog. Mist gathers in both living beings and stones called magicite. Anyone, either wielding these stones or not, can extract mist to use magic. A form of magicite, nethicite, absorbs mist, thus nullifying any magic effects. If deifacted nethicite absorbs too much mist, it will release it suddenly if someone tries to extract it, resulting in a violent explosion. Manufacted nethicite cannot handle too much mist, simply shattering if it absorbs too much.
The viera are sensitive to mist; if they are exposed to too much, they will go into a "mist frenzy", their strength increases and they will attack anyone who gets in their way. When captured on the Shiva, the mist from the Dawn Shard drives Fran berserk, and for gameplay purposes places her in Berserk status. She also enters mist frenzy when she enters the top chamber of the Pharos which houses the Sun-Cryst, but the sheer concentration of mist energy causes her to lose consciousness instead.
Using mist, the Occuria can manipulate people. While the viera Mjrn is under the influence of manufacted nethicite, the rogue Occuria Venat controls her and the same happens to Judge Bergan. Ashe and Vaan see illusions of Ashe's late husband, Lord Rasler in areas with abundant mist, revealed to be apparitions conjured by the Occuria. When the mist becomes thick enough other people are also able to see the illusion.
Mist comes in different colors depending on whether it is active or cooled. Active mist, such as that found in a nethicite explosion, is bright gold orange, whereas cooled (inactive) mist is a darker gold with subtle blue and green overtones. The most notable sights of cooled mist in the game are in the Edge of Reason, in the Feywood, just before entering Giruvegan, and the areas just before fighting an Esper.
Mist serves a few gameplay functions outside the storyline. In areas where mist is thick, such as the Nabreus Deadlands, Feywood, Necrohol of Nabudis, and The Great Crystal, MP recovers at a faster rate than normal. In Giruvegan, Diakon Entites appear in areas where the mist is thick, and in the Nabreus Deadlands, Leamonde Entites appears only during misty weather. Though viera are seen going berserk multiple times when exposed to mist, Fran suffers no ill effects when fighting in these areas, save for the one incident aboard the Shiva as mentioned above. At some points during storyline events, heavy mist will prevent the usage of Gate Crystals.
Mist also serves as an indicator of Esper activity. Should an area where an Esper is bound is encountered, Mist begins to appear and fade in steady intervals. And if the Mist grows too thick, it indicates that an Esper is just nearby.
Mist continues to become the source of magick in Ivalice. When one is about to cast his or her spell, they must wait for mist to build up before they can do so. Usually, this restoration amounts to 10 MP unless effected by an outside force, such as a Clan Privilege.
Mist also serves as one of the four possible weather conditions in Final Fantasy Tactics A2. The magick is immediately characterized as a billowing golden fog that can breed various strains of monsters and imbue weaker beings with adverse effects. Mist is especially prevalent at the Aldanna Range and Zellea, the Forbidden Land. At least one ability, the Geomancer's Mist Storm, can only be used when the mist is active.
Mist is an ability exclusive to the Misterian race which Makenshi and Madoushi belong to. It is created from their bodies in the form of their breath, thus they wear masks to control the amount they release. They keep a stock in bottles around their waists, and are able to use them to summon Sword Dragons.