Final Fantasy X Cheats

Get Secret Overdrive for Valefor
To get this overdrive you have to go to Besaid Island and talk to the women in the Weapons store. She will tell you about her dog digging up something. Next go to the Clothe Shop (Top Right Hut) and go up to the Dog press X and Valefor will Learn Energy Blast.
This does Double the damage Energy Ray does.