For those who have not completed Xenoblade Chronicles, this page or section may contain spoilers regarding the plot. Discretion is advised.
A character's Talent Gauge is a measure of how close a character is to being able to use their Talent Art, or how close they are to other side effects that come from a full Talent Gauge. Unlike normal arts, Talent Arts have no cooldown, and will not refill over time, and thus a character must manually refill their Talent Gauge on their own.
Filling the Talent Gauge
Every character has their own means of filling the Talent Gauge. With a Talent Boost gem, every character can use Auto Attacks to fill their Talent Gauge, but this will come at the cost of Auto Attack damage. If a character performs a Double Attack, their Talent Gauge will fill with each hit. Talent Gauges are not susceptible to the effects of Arts Seal.
Unlike the cool down gauges for other arts, the exact state of a Talent Gauge will be carried over into and out of a Chain Attack. If one wishes to perform a Talent Art during a Chain Attack, the gauge will have to filled prior to starting the attack, or otherwise be filled during the Chain Attack with arts that are capable of doing so.
Haste Gems and Double Attack gems are often used to expedite the process of filling a character's Talent Gauge by speeding up their Auto-Attack rate. A character's aggro gain should be considered when doing this, however.
Shulk can fill his Talent Gauge at the cost of half of his HP with Battle Soul, and the amount of Talent Gauge he gets in return increases with the level of the art. Shulk's Stream Edge is capable of hitting multiple enemies, and will award him 15% of the Talent Gauge for each enemy hit.
Each Monado Art will empty the Talent Gauge by a different amount. Monado Buster will empty the Talent Gauge by 100%, but Monado Enchant may be used in exchange for only 50%. Despite this, no Monado Arts can be used until Shulk performs Activate Monado, which cannot be done unless the Talent Gauge is completely filled.
Reyn's Talent Art, Mad Taunt, will have its gauge filled with each Auto Attack. Bone Upper will fill the Talent Gauge by a certain amount when it hits an enemy (depending on the art's level), and War Swing, like Stream Edge, will fill the Gauge for every enemy it hits. War Swing fills the Gauge by 10% and hits four times, but as an area attack, it will also fill up for each enemy hit. If two enemies take all four hits of War Swing, Reyn will have 80% of his Talent Gauge filled.
Reyn's Talent Gauge, when full, can also be used for his ether art, Magnum Charge. Upon using this art, his Talent Gauge will be completely emptied and his next art used will do more damage. Magnum Charge, as a regular art, also has a cooldown, and will need to be both fully cooled down and be given a full Talent Gauge before it can be used. Because it is not a true Talent Art, Magnum Charge is susceptible to Arts Seal.
Unlike other Talent Arts, Sharla's Cool Off can be used no matter how full her gauge is, provided it is not empty. If her gauge fills up, however, she is forced to Cool Off and will automatically use this art. Rather than emptying the entire gauge at once, though, Cool Off will slowly lower the talent gauge over time while the art is in effect, and will not end until the gauge has reached 0%. Therefore, the exact duration of the art is entirely based on the level of Sharla's Talent Gauge. Cool Off cannot be performed during a Chain Attack. If Cool Off is already in effect when the Chain Attack is initiated, Sharla will be excluded from the Chain Attack and will not be able to join.
Auto attacks will not fill her talent gauge unless she is holding a Talent Boost gem. As an alternative to the Talent Boost gem, Sharla may equip a Heat Sink gem, which will decrease the rate at which her talent gauge fills. Sharla's Talent Gauge can also be emptied twice as fast with the Ultimate Sniper skill.
Sharla's Talent Gauge will automatically be emptied following the end of each battle.
Dunban can fill his Talent Gauge by 50% in exchange for 20% of his health with Final Flicker though, unlike Shulk's Battle Soul, these values are fixed and will not increase or decrease by leveling up his art.
With Soaring Tempest, Dunban will perform a four-hit area attack that will fill his Talent Gauge by 10% for each hit. The rules for this art are identical to Reyn's War Swing.
If Dunban is incapacitated while his Jaws of Death aura is active, he will gain 50% of his Talent Gauge upon revival. If his Battle Eye aura is active, he will have his Talent Gauge filled for each attack he dodges.
Elemental Discharge can be used no matter how much of her Talent Gauge is filled, even it is empty. The only requirement is that she have at least one summoned elemental, granted by either Summon Bolt, Summon Flare, Summon Wind, Summon Ice, Summon Earth, or Summon Aqua (or subsequently granted by Summon Copy). Elemental Discharge does not rely on the cooldowns for these arts, however, and can be used as long the elemental was successfully summoned.
With each use of her Talent Art, her Gauge will actually be filled, and upon reaching 100%, Melia will enter the aura 'Elemental Burst'. In this aura, all subsequent uses of Elemental Discharge will deal double damage, and the aura will last as long as her Talent Gauge remains at 100%. If Elemental Discharge is performed three times in this state, her Talent Gauge will immediately be emptied.
During Elemental Burst, Melia will gain access to the ether arts Burst End and Mind Blast. These arts do not consume her Talent Gauge at all, and can be used as many times as desired, provided the player is willing to wait for them to cool down before emptying her Talent Gauge.
If Melia's Talent Gauge is full at the end of a battle, she will retain a near-full Talent Gauge upon the start of the next battle, and her gauge can then be filled with just one attack in this state.
Unlike other characters, Riki has no arts or skills that are capable of filling his Talent Gauge, instead being given an art that fills the Party Gauge (Happy Happy). Riki's Talent Art can be given the ability to steal AP and EXP with the AP for All! and EXP for All! skills.
The Talent Gauges for Fiora's Butterfly Step, Sword Drones, Gun Drones, Cannon Drones, and Shield Drones are all filled by performing Auto Attacks and emptied by performing the respective art. Fiora's Auto Attacks are performed twice at a time, and will fill her Talent Gauge for each hit. This also applies to her Double Attacks, which will fill her Talent Gauge for each of the four hits.
Fiora's Vital Force skill will give her a 2% chance of maxing out her Talent Gauge whenever she deals damage, whether that damage comes from an Auto Attack or an Art. This is a linkable skill and can be given to any character with a circle link to allow them to max out their Talent Gauges, though it comes with a hefty cost of 75 Affinity Coins. Fiora's Explosion of Energy (from the same Skill Tree) skill will raise her Tension by one full level whenever she performs a Talent Art, and this too can be equipped to other characters for a cost of 80 coins.