Flash

Location
Flash is located in the second main screen of Suhalla Desert, in its general middle-left area. Before you climb down a short wall onto the sandy ground below, where you would be chased by the huge tornado containing the Storm Lizard boss, cast Reveal to see a series of small black footsteps leading up to the left. Cast Reveal at where they would end to show that there is an otherwise invisible log pillar against a wall that you can hop across to the left. Flash is in plain sight after that, and it must be defeated in battle to be acquired.

As an opponent
Statistically, Flash has 592 HP, 52 PP, 253 Attack, 65 Defense, 151 Agility, and 17 Luck. Like all other Mars Djinn that are fought, in terms of resistance, it has a Mars Resistance rating of 193, Venus and Jupiter Resistance ratings of 100 each, and a Mercury Resistance rating of 25, and in regards to its abilities it uses its available Mars-based attacks with a Mars power rating of 125.

Flash can use the following battle commands:
 * Fireball: Used 53 out of 256 times, this is a Psynergy spell that projects a moderately large amount of fiery spheres that arc over and into the party's position, dealing a Mars-based attack with a power rating of 65 and a range of 5. This ability consumes 12 of its user's PP.
 * Nova: Used 47 out of 256 times, this is a Psynergy spell that causes a large explosion of fire to discharge at the party's position, dealing a Mars-based attack with a power rating of 70 and a range of 5. This ability consumes 13 of its user's PP.
 * Flare Storm: Used 41 out of 256 times, this is a Psynergy spell that causes three patches of fire stacked on top of each other to go through multiple Adepts and deal a Mars-based attack with a power rating of 80 and a range of 3. This ability consumes 12 of its user's PP.
 * Eruption: Used 35 out of 256 times, this is a Psynergy spell that causes two fiery pillars to explode at the party's position, dealing a Mars-based attack with a power rating of 90 and a range of 3. This ability consumes 14 of its user's PP.
 * Fiery Blast: Used 29 out of 256 times, this is a Psynergy spell that creates a large lava-like explosion, dealing a Mars-based attack with a power rating of 110 and a range of 5. This ability consumes 19 of its user's PP; Flash's PP meter is sufficient for two usages at most.
 * Attack: Used 28 out of 256 times, this is this monster's standard physical attack, but for this monster it is counted as a Mars-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.

When defeated, Flash yields 460 EXP and 445 Coins, and the Flash Djinni is added to your party's Djinn collection. If you fell it with an offensive Mercury Djinni like Mist, its rewards increase to 598 EXP and 578 Coins.

Flash should be no problem to blow away with summon spells - and if it happens to flee the first turn it gets, an available exit to use to get Flash to reappear is literally right in front of you.

Description
When Set, it increases base HP by 14, base PP by 3, and base Defense by 2.

When Flash's battle effect is used, all damage done to all current battling party members is reduced by 90% for the duration of that turn, and this effect is always cast first regardless of the user’s Agility. Flash and the similar, lesser Djinn Granite and Shade share the same priority bracket as the Ground and Petra Djinn, meaning that if two units use any of these abilities, the one with the higher agility will act first.

Ability analysis
Calling Flash notable among Djinn is an understatement; it is widely considered the single best Djinni in the entire series. An Adept using up their turn to make all four Adepts next to invincible throughout the entire turn without fail is an incredible trade off, and goes a long way to making the rest of each game a lot more manageable. During a turn where all damage dealt against you goes in a range between 7 and 15 or so, the party may safely heal itself without the risk of any low-health party members to be downed by a strong attack before your healer, such as Mia and her Wish Psynergy series, gets around to their action. Flash is the best Djinni both in Golden Sun from when it is first found onward, and in The Lost Age starting from when Isaac's party joins Felix's along with all their respective returning Djinn (granted that Password data transfer is in effect).

Flash is widely considered a broken effect in Vs. play, as it prevents the party from being damaged by the strongest of the opponent party's summons. Oftentimes, Flash is banned from usage in this environment. It is possible for the opponent party to nullify Flash with an in-game battle effect, though; the Ground and Petra Venus Djinn, which prevent a target from taking an action in a given turn, have a "strike first" property that can make them even faster than Flash as long as the user of Ground/Petra has a higher agility rating than the Flash user, so those can be used against a Flash-using Adept to leave the party open for a summoning barrage.

Name Origin
A flash is a burst of bright light occurring for a short period of time, possibly why this Djinn was given an ability that always goes first.