Harmonics

Harmonics ハーモニクス (haamonikusu) is one of staples of the games in the Universe of EXA_PICO, and it is a special technique used between Vanguards and Reyvateils/Crafters to strengthen each other mutually. It is based on the principle of the Vanguards fighting well, which moves the heart of the singer and allows her to sing faster and her song to exhibit more power. This in exchange also further enhances the attacks of the Vanguards.

Ar tonelico: Melody of Elemia
The first game in the Ar tonelico series was also the one that introduced the concept of Harmonics. This technique is used in Sol Ciel only by the inhabitants of the city of Platina: the Apostles of Elemia, and it is done by applying special properties to their weapons and fighting in a way that moves the heart of the Reyvateil they are protecting.

In-game, this is represented by the two bars located at the bottom of the screen: the blue bar represents the actions of the Vanguards, while the pink bar represents the emotional state of the Reyvateil. The blue bar increases as the Vanguards land attacks on the enemies and decreases when they receive damage. On the other hand, the pink bar increases when any party member takes any actions aside of standing idle, while it decreases when the Reyvateil suffers damage.

When both bars meet, one of the gray crystals located above both bars: the Harmocrystals, will light up in pink, and this will turn increase the Reyvateil's Burst Speed and Song Magic damage, as well as increasing the damage dealt by the Vanguards. However, initially only one crystal is available, so the player must make the Reyvateil use her Song Magic to fill a small red bar located next to the Harmocrystals called the Limit Bar: whenever it completely fills up, another empty Harmocrystal will appear, allowing the player to increase the Harmonics level up to three times.

When two Harmocrystals are filled, the basic attacks of the party members will change to a more powerful version, such as Lyner's Dive Slash changing into Full Stomp, allowing them to dish more damage in battle. Additionally, the party members will be allowed to use their special skills only when the number of Harmocrystals correspoding to the level of the skill have been filled, meaning they will only be allowed to use their best attacks when all Harmocrystals are filled.

However, the Harmonics level can be dropped if the characters receive enough damage for both bars to disappear from the screen, while using a Counter after blocking a Stored Attack will always consume a Harmocrystal. Additionally, if the Reyvateil gets killed at any point during the battle, all the Harmocrystals will be emptied and both Harmonics bars will be reduced to zero, so the player will have to build their Harmonics level back from the start if that happens.

The game's drop system is also directly tied to the Harmonics level: the higher the level the player could reach by the time the battle ends, the higher the category of the items the enemies will drop. Therefore, it's highly desirable to reach the max Harmonics level during boss battles due to them dropping unique items or Grathnode Crystals that can't be gotten anywhere else. The player shouldn't also worry much about maintaining the level: once they hit the max Harmonics level, they are guaranteed to get all the items dropped by the enemies once the battle ends. However, this also has the disadvantage of drawing out some battles, as well as not allowing the player to get any but the most basic drops when there isn't a Reyvateil present in the party.

Finally, the Harmonics Trend parameter in the Reyvateil's status screen indicates how fast the pink Harmonics gauge increases whenever a party member takes action

Ar tonelico II: Melody of Metafalica
In Ar tonelico II, the Harmonics concept is maintained, but only as part of the Emotion Indicator system that was introduced into the battle system. Harmonics corresponds to the attacks executed by pressing the action button for a Vanguard while holding Up on the D-Pad, which allows to use attacks balanced in speed and power.

When enough Harmonics attacks are used to fill the Harmonic trend of the Indicator, it bestows the bonus of increasing the invisible Harmonics Level of the Reyvateil protected by the Vanguard that struck the blow that filled the trend, allowing Vanguards to use their Lv. 2 and Lv. 3 skills after they have learned them, increasing the damage from their attacks as well as the speed at which the Reyvateils' Burst Gauge fills, and also raising the likelihood of obtaining dropped items after the battle ends, as indicated in the following table.

Additionally, increasing Cloche's Harmonics Level while she is in the battle party also allows her to make use of Replekia after she has gained access to it. Therefore, the player must have her in the active party and increase her Harmonics Level if they wish to use that powerful ability.

Ar tonelico Qoga: Knell of Ar Ciel
While the Harmonics ability is never mentioned by name in Ar tonelico Qoga, it is theorized that the Beat Ups on which the Reyvateils depend to execute their Purges actually come from Harmonics, given that they retains the elements of fighting in a way that moves the Reyvateil, and the indicator showing her emotional state in a way that serves as a guideline for the Vanguards is called the Harmograph.

Similarly, the Ultra Supermoves also seem to be based on Harmonics due to the Burst consumption they have and the fact that the Vanguards empathize with the Reyvateils by Purging themselves to execute them.

Ar nosurge: Ode to an Unborn Star
The first RPG in the Surge Concerto series also makes use of the Harmonics concept, and true to its roots, it still focuses on fighting in a stylish way to move the Crafter's heart to make her Song Magic more powerful.

This is represented by the Harmo Level, which is located at the bottom right of the battle interface. Initially, players can only raise the Harmo Level to Lv. 1, but they will be able to raise it further the more they progress through the Heroine's Genometrics. It should be noted that Ion and Casty are independent, so the Harmo Level progress gotten in one won't be carried to the other.

Also, the higher the Harmo Level, the harder it will be to raise it: to go from Lv. 0 to Lv. 1, the player only has to fill the bar up to a quarter of it, but to go from Lv. 3 to Lv. 4, they must fill the bar in full. And it also must be mentioned that the Heroine won't be able to release the Song Magic she is charging if the Harmo Level isn't raised to at least Lv. 1.

The Harmo Gauge is filled by attacking the enemies and making large Chains, as well as Breaking them as much as possible. Similarly, defending well the Heroine during the Enemy's Turn will also increase the Harmo Gauge. On the other hand, poorly guarding the Heroine will decrease the Harmo Gauge, though luckily the level can't be dropped once it has been raised. The Gauge can also be drained by using the powered-up attacks the player can use by holding either R1 or L1 during their turn, which turns it red and gives access to more powerful skills, though they will become unavailable when the gauge is about to get empty.

Finally, once the players have completed the entirety of the heroine's Genometrics, they will be bestowed a final skill called the HarmoBurst. This is executed by filling the Harmo Gauge once it has gotten to Lv. 4, which will replace the default Song Magic option in the Start button menu. Once activated, the player will be able to attack enemies until the Harmo Gauge gets completely depleted, as using this skill will constantly drain it. Midway through, they will be able to press the Circle button to activate the ultimate skill of the protagonist they are using, which will then be followed by the Song Magic of the Heroine with amplified strength.