This gauge will increase every time you deal damage to an enemy.
Also, when the Break Gauge fills to 1, you can use a Break Attack, and the gauge can fill up to a max of 4.
The Break Gauge will reset after every battle.

When a set amount of the Break Gauge is filled, a character can use their special attack, the Break Attack. You can activate a Break Attack by pressing the L3 button, along with the button assigned to a specific character (○ button, △ button, □ button, × button).