Zephyr

Zephyr (バイス Bise) is a Jupiter Djinni found in Golden Sun and Golden Sun: The Lost Age.

Zephyr is the third Jupiter Djinni in the original Golden Sun,  and can also be  acquired in Golden   Sun: The  Lost  Age. Although it is not the party's third Jupiter Djinni in The  Lost Age,  Zephyr is still ordered as the third Jupiter Djinni  when  equipped to  characters. Because it is not available until after most  other Jupiter Djinn can be found, however, the separate Djinn list viewable with the  Select button from the status screen lists Zephyr and all other Jupiter Djinn from Golden Sun after all of the Djinn introduced in The  Lost Age. According to this order, Zephyr is the fourteenth Jupiter Djinni in The Lost Age rather than the third, but this order has no influence elsewhere in the game.

Basic description

 * "Boost party Agility with a swift wind."

When Set, Zephyr increases its Adept's base HP by 10, base PP by 3, base Agility by 2, and base Luck by 1.

When Zephyr is unleashed in battle, all currently active and alive Adepts get their Agility ratings temporarily buffed to +100%, the maximum agility bonus possible. It doubles everyone's speed, in other words.

In Golden Sun and The  Lost Age, Zephyr's unleash animation visually resembles a glowing purple image of a Jupiter Djinni floating above the party while collections of small, glowing purple energy orbs gather into each Adept in order, and then each Adept is surrounded with a brief windy effect to indicate a speed boost.

Locations
Golden Sun: Zephyr is located in the Fuchin Falls Cave dungeon, in a room with water that is crossed by rolling logs. It shouldn't be hard to figure out how to reach it, which is by rolling on the top horizontal log down,  rolling the lower left vertical log one space left, rolling the  horizontal log back up, hopping to the lower left vertical log, and  rolling it right. Zephyr must be battled to be obtained.

Golden Sun: The Lost Age: Players can transfer data from Golden  Sun   to The Lost  Age,  but even  if they don't, Zephyr will be  among the Djinn Isaac's party has with  them when they join forces with  Felix's party late in the  game.

As an opponent (Golden Sun)
Statistically, Zephyr has 314 HP, 25 PP, 115 Attack, 26 Defense, 68  Agility, and 9 Luck. Like all other Jupiter Djinn that are fought, in terms of resistance, it has a Jupiter Resistance rating of  193, Mercury and Mars Resistance ratings of 100 each, and a Venus  Resistance rating of 25, and in regards to its abilities it uses its  available Jupiter-based attacks with a Jupiter power rating of 125.

Zephyr can use the following battle commands:
 * Whirlwind: Used 53 out of 256 times, this is a Psynergy spell that causes a  large whirlwind laced with electric charges to spin through the enemy  party, dealing a Jupiter-based attack with a power rating of 20 and a  range of 3. This ability consumes 5 of its user's PP.
 * Flash Bolt: Used 47 out of 256 times, this is a Psynergy spell that  causes two purple lightning bolts to strike at the party briefly,  dealing a Jupiter-based attack with a power rating of 40 and a range of  3. This ability consumes 7 of its user's PP.
 * Plasma: Used 41 out of 256 times, this is a Psynergy spell that causes a single,  large bolt of purplish lightning bolts to strike at the party and  explode on impact, dealing a Jupiter-based attack with a power rating of  45 and a range of 3. This ability consumes 8 of its user's PP.
 * Wind Slash: Used 35 out of 256 times, this is a Psynergy spell that  shoots out a moderately large purple air swath at each Adept, dealing a  Jupiter-based attack with a power rating of 50 and a range of 3. This  ability consumes 9 of its user's PP.
 * Storm Ray: Used 29 out of 256 times, this is a Psynergy spell that causes a moderately  large array of purple lightning bolts to thoroughly assault the party,  dealing a Jupiter-based attack with a power rating of 65 and a range of  3. This ability consumes 10 of its user's PP.
 * Attack: Used 28 out of 256 times, this is this monster's standard physical attack, but for this monster it is counted as a  Jupiter-based attack rather than a non-elemental attack.
 * Flee: Used 23 out of 256 times, this enemy has the ability to attempt to Flee  the battle, thereby ending the battle if successful without rewarding  you with the associated EXP, Coins, and the Djinni itself, and the  Jupiter Djinni disappears from its field spot. If this happens to you,  you should walk down to the lowest horizontal log below, roll it all the  way up to the top of the room, enter and exit the doorway there, and  reverse your direction back to the Djinni

When defeated, Zephyr yields 150 EXP and 176 Coins, and the Zephyr Djinni  is added to your party's Djinn collection. If you fell it with an offensive Venus Djinni like Flint, its rewards increase to 195 EXP  and 228 Coins.

Ideally, all party members should have two Djinn each, so if simply attacking it isn't enough to fell it before  it happens to flee, then try summoning Ramses, Kirin,  Atalanta, and Nereid in one turn. Storm Ray would be its strongest attack, though its least used.

Analysis
General: Using a turn to double all Adepts' agility ratings basically solves all possible issues of each one of your Adepts not moving before the enemy in a given turn, for several turns. Depending on the boss, this can be highly useful, though it can be argued that a Djinni that halves all enemy Agility ratings is the same, such as the Venus Djinni Vine. There is one advantage the latter has over doubling party agility, though; since the agility boost counts as a buff, it can be removed by the Break Psynergy if the boss has it (such as Deadbeard). But a Djinni that halves the enemy's Agility is something that no enemy in any game can dispel from themselves. In Dark Dawn, identical equivalents to Zephyr are the Jupiter Djinni Fleet and the Mercury Djinni Torrent.

By game
Golden Sun: Zephyr is the only effect that increases agility in any way, and is the one Djinni that doubles everyone's speed. This makes it very useful, perhaps life-saving, to use all throughout the game, particularly  against bosses, allowing you several turns where your party can safely  attack and heal themselves before the enemy gets to take its action(s)  those turns.

Golden Sun: The Lost Age: When Isaac's party joins Felix's party along with their returning Djinn, Zephyr's ability makes it a second Coal, a Mars Djinni with the  exact same effect that the TLA party finds in the middle of that game,  and these two together remain the only form of Agility enhancement in  the series. They continue to be extremely practical if the player decides to use them specifically during boss fights where the boss  happens to be faster than several Adepts and that proves to be a  problem.

Name Origin
Zephyr is named after the Greek god of the west wind, Zephyrus. Often thought of as the gentlest of the winds, Zephyrus was a clear counterpart to the god of the north wind, Boreas. Baisu is most likely a mispronuncation on the Japanese's part of the French word Bise, referring to a particular cold and dry northeast wind, but one that is accompanied by clear blue skies (though at times, it can carry dark storm clouds). It also means colloquially in French a light kiss on the cheek, given as a greeting or parting to friends and family. The root is Germanic in origin.