Well I found it pretty easy to get limit breaks on disk 2. Go to cactur island and manipulate him then using 1000 needles on yourself. With a hyper and mid level (30-50) you will gain more limit based on your HP. After you do the first limit so many times you will gain the second. Now it's time to get in the highwind and go to the forest outside of Rocket Town. Kill a bunch of enemies with that person and you will gain the next limit break in about 10-20 minutes of fighting.