Charge up your Chi gauge to the maximum level. When you enter a battle, kill all the enemies except for one using sword attacks, then weaken the last one. Next, use the Chi attack to kill the weakened enemy. After you start the Chi attack, hold Square. Once the enemy is dead, you will begin to charge your Chi gauge, but will still be in Attack mode, even though there are no enemies. When the gauge is charged, tap Square(2), then hold it down again (requires precise timing). If done correctly, you will execute the Chi attack and begin charging up again. You will gain Chi experience for each Chi attack. Repeat this as many times as desired. Note - If the timing of the Square double tap is incorrect, you will exit Battle mode and be unable to attack with your Chi.