* Level up your character. As your character levels up, their full power bar will increase.
* Equip power-up items. There are a number of power-up items that can be found in the game that will increase your full power bar.
* Use certain special attacks. Some special attacks, such as the "Super Charge" attack, can temporarily increase your full power bar.
* Use the "Power Boost" ability. The "Power Boost" ability is a special ability that can be unlocked by completing certain challenges in the game. When activated, this ability will increase your full power bar by 50%.