Sour

Sour is a Mercury Djinni found in Golden Sun: The Lost Age.

Sour is the second Mercury Djinni in Golden Sun: The Lost Age. The separate Djinn list viewable with the Select button from the status screen lists Sour and all other Mercury Djinn introduced in The Lost Age before the seven Mercury Djinn from the original Golden Sun, most likely because all the Djinn from the original game can be gotten all at once late in The Lost Age. However, the original Djinn are ordered before all of the Djinn introduced in The Lost Age in the Djinn inventory screen while they are allocated to characters. By this order, Sour is the ninth Mercury Djinni in the GBA series, rather than the second.

Basic description

 * "Reduce a foe's resistance."

When Set, Sour increases its Adept's base HP by 8, base Psynergy Points by 4, and base Attack by 3.

When Sour is unleashed in battle, the user deals a Mercury-based attack equal in power to the user's normal physical attack multiplied by 1.5x. Then there is a chance the target's Resistances will be lowered by 40 ("two stages", the same amount as the Weaken Psynergy. The most Resistances can be lowered down by is 80, as in "four stages".)

Visually, Sour's unleash animation resembles the user making a strong, Mercury-aligned hit, and after the hit the purple-shield-shattering effect plays out at the enemy's position to indicate that the attempt to lower the target's Resistances has been made.

Damage calculation
Elemental physical attacks such as Sour use the damage dealt by the attacker's standard physical attack as the base damage to be later modified. The total amount of damage dealt by a normal physical attack is half the difference between the attacker's Attack statistic and the target's Defense statistic, as this equation shows:


 * ''base damage = (Attacker's Attack - Target's Defense) / 2

Sour's attack then takes this base damage value and uses it in the following equation:


 * ''final damage = (base damage * 1.5) * (1 + (Attacker's Mercury Power - Target's Mercury. Resistance) / 400)

To word this in prose, Sour takes the base damage of the user's normal physical attack, multiplies it by 1.5, and then this result is modified by how much higher or lower the user's Mercury Power is than the target's Mercury Resistance. The difference between the user's Mercury Power and the target's Mercury Resistance is divided by 400, then 1 is added to this, resulting in what can be called the "elemental damage multiplier". This number is what Sour's damage is multiplied by.

For example, if an Adept with an Attack rating of 100 and a Mercury Power of 120 unleashes Sour on a monster with a defense of 20 and a Mercury Resistance of 70:


 * damage = ((Attack - Defense) / 2 * 1.5) * (1 + (Power - Resistance) / 400)
 * damage = ((100 - 20) / 2 * 1.5) * (1 + (120 - 70) / 400)
 * damage = ( / 2 * 1.5) * (1 + / 400
 * damage = ( * 1.5) * (1 + )
 * damage = *
 * damage = 67

Therefore, if Sour were to be unleashed under these circumstances it would deal 67 points of damage.

Location
Golden Sun: The Lost Age: Sour is a Djinni that is randomly encountered in a specific area of the overworld that otherwise appears to be pointless scenery. Thus, it is very often missed by players playing the game the first time without any outside information. The battle with Sour may ensue in place of a random battle in the pictured area northeast of the town of Mikasalla and just below the cavern containing the Megaera summon tablet. It must be defeated to be acquired.

As an opponent (The Lost Age)
Statistically, Sour has 291 HP, 26 PP, 75 Attack, 19 Defense, 57 Agility, and 9 Luck. Like all other Mercury Djinn that are fought, in terms of resistance, it has a Mercury Resistance rating of 193, Venus and Jupiter Resistance ratings of 100 each, and a Mars Resistance rating of 25, and in regards to its abilities it uses its available Mercury-based attacks with a Mercury power rating of 125.

Sour can use the following battle commands:
 * Cool: Used 53 out of 256 times, this is a Psynergy spell that summons a small group of icy spikes out from the ground at the opposition, dealing a Mercury-based attack with a power rating of 35 and a range of 3. This ability consumes 6 of its user's PP.
 * Ice: Used 47 out of 256 times, this is a Psynergy spell that shoots a mass of ice spikes down onto a target Adept, dealing a Mercury-based attack with a power rating of 35. This ability consumes 5 of its user's PP.
 * Froth: used 41 out of 256 times, this is a Psynergy spell that projects a small array of watery spheres that arc into the party, dealing a Mercury-based attack with a power rating of 28 and a range of 3. This ability consumes 5 of its user's PP.
 * Douse: Used 35 out of 256 times, this is a Psynergy spell that causes a small array of watery spheres to drop onto the targeted Adepts, dealing a Mercury-based attack with a power rating of 25 and a range of 3. This ability consumes 5 of its user's PP.
 * Frost: Used 29 out of 256 times, this is a Psynergy spell that drops shards of ice onto the party, dealing a Mercury-based attack with a power rating of 20 and a range of 3. This ability consumes 5 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 Mercury-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. Since this is a randomly battled overworld Djinni, however, it can be very quickly fought again just by running around in the same area you first fought it in.

When defeated, Sour yields 130 EXP and 152 coins and the Sour Djinni is added to your party's Djinn collection. If you fell it with an offensive Mars Djinni like Cannon, its rewards increase to 169 EXP and 197 Coins.

The Fume Psynergy is still the most useful Psynergy to use against Sour in the interest of knocking it out quickly, and if you collected Iron near Madra you have the two Djinn needed to summon Ramses as a moderately powerful offense as well. You should also be at a high enough level for Sheba to be able to use Plasma.

Analysis
General: Sour is an ideal attacking Mercury Djinni because it has a moderately strong damage multiplier of x1.5, which means it is likely to produce satisfactory damage results when Unleashed by an Adept with a high attack rating. Mercury Djinn do not get higher damage multipliers, so Sour will only become more usefully damaging as the game progresses all the way up to its end. Sour has a relevantly beneficial side effect to boot; its chance to lower the target's Resistances will increase all damage the target will take from any subsequent attacks that are aligned with any of the element, therefore making the enemy fall faster, even though the difference the resistance drop makes probably isn't all that high. It has an identical counterpart in the Mercury Djinni Claw in Golden Sun: Dark Dawn.

By game
Golden Sun: The Lost Age: Sour is the one Djinni in either GBA game that deals an attack and has a chance to drop the target's Resistances by a hefty amount (equal to the Weaken Psynergy). This is good flavoring to what is already one of the best attacking Mercury Djinn in the game; a 1.5x damage multiplier is matched only by the later Mercury Djinni Gel (and to compare secondary effects, Gel has a chance to drop the target's Attack rating by 25%; many prefer the sharp drop to resistance because that is much more likely to be taken advantage of, since an attack-dropped enemy won't always use an ability that will be hindered by the lowered attack rating). Another benefit to Sour is that despite being one of the best attacking Mercury Djinn especially from an endgame perspective, it is found very early in the game. Aside from Gel, perhaps the only other Mercury-element attacking Djinni that matches Sour in terms of overall value is Serac, which does a high amount of bonus set damage and has a chance to instantly kill the target.

If you have Sour and the previous Mercury Djinni Fog at the early point in the game in Osenia (the point in the game when the Mercury Adept Piers hasn't joined yet), you can consider having these two Djinn be set onto one of the three Adepts to put them in the second stage of what their Mercury-combining class series would be. Furthermore, you may have both of these Mercury Djinn On Standby once your party fights Briggs in Alhafra - even though your other Djinn will be contributing to your Adepts' classes, you are allowed a free Nereid summon, though you should be mindful of what Adepts these two Djinn are present on because when they automatically Set themselves back they will change the Adepts' classes, likely for the worse. Try to put both Mercury Djinn on one Adept in this case so that when both Djinn are Set it will put the Adept in an improved class.

Name Orgin
At first glance, Sour seems like an unlikely name for a Mercury Djinni. However, sourness is the taste that detects acidity. Acids are typically considered liquids or are associated with them, hence the reason Sour is a Mercury Djinni. Acids also corrode, which fits the side effect of the Djinni.