Valefor

Location: First Aeon, acquired in Besaid Temple

Unique Attack: Sonic Wings
Slightly delays enemy's next turn, deals physical damage.

Magic
Black: Fire, Blizzard, Water, Thunder

Overdrive: Energy Ray, Energy Blast
To obtain Valefor's second overdrive, Energy Blast, return to Besaid village later in the game with Yuna in your party. Speak to the little girl outside the temple. (If she is not there, she may be in the item shop.) She will give you an item which enables this overdrive. Energy Blast is similar to Energy Ray but it does more damage at the cost of a longer recovery time.

After you've activated Yuna's Legendary Weapon, Nirvana, Valefor will be able to break the 9999 damage limit.