Impulse is a rank 6 command ability used by Bahamut, which merely inflicts non-elemental damage to all enemies. It is also used as an enemy ability by enemy Bahamuts and Dark Bahamut, where it also inflicts Delay. Dark Bahamut's version has the added effect of inflicting Petrify, which can shatter a character if it also KO's them. In addition to Petrify, it can also inflict Slow, Full Break, and strong delay. Slow will ignore immunities to the status, but can still be countered via Auto-Haste.
Impulse is an aerial magical Bravery Attack for Yuna, known by default. It requires 80 AP to master and 30 CP to equip (15 if mastered), and has Ranged Low priority. By holding the button, Impulse can be charged to fire four separate projectiles with strong homing. Impulse is also seen in Yuna's EX Burst.