Final Fantasy X-2: Blue Bullet Guide

The Gun Mage dress sphere (which can be acquired in either Chapter 1 or Chapter 2) will come with the "Blue Bullet" ability, which is essentially the same "Blue Magic" ability that's appeared in other Final Fantasy games.

If you're fighting an enemy that's using an ability that can be learned, and one of the girls is wearing the Gun Mage dress sphere, and the the enemy attacks with that specific ability, the ability will be learned (and can now be used). Interestingly enough, the character wearing the Gun Mage dress sphere doesn't even need to survive the attack to learn the skill.

16 Blue Bullet abilities are available in total, but two of them will be especially hard to acquire. The first 14 Blue Bullet skills are offensive, so it's natural that the enemy would try to cast them on your party, but the final two are defensive, so it may be a bit more tricky.

To learn the two defensive Blue Bullet abilities (White Wind and Mighty Guard), you'll need to cast confuse on the enemy. Full Throttle's Crazy Wing, Dark Knight's Confuse, Floral Fallal's Panic Floralysis, Machina Maw's Confuse Missile, Lady Luck's Tantalize, and Alchemist's Blaster Mine mix (used most easily by combining a Potion with a Sleep Grenade) will all work. Once the enemy's confused, wait for them to heal your party. This may take some patience.