Dark Valefor Dark Valefor is an optional boss in the International , PAL and " HD Remaster " versions of " Final Fantasy X " . She guards the entrance to Besaid Village when the party returns after obtaining the " Fahrenheit " , and must be defeated to acquire Anima in case the player did not obtain the treasure chest in the Besaid Temple earlier . Battle . Dark Valefor uses physical attacks and Sonic Wings , which inflict Delay ( weak ) . Dark Valefor can also use Energy Ray at any time . Unlike the summon Valefor ' s Energy Ray , Dark Valefor ' s Energy Ray is considered magical damage and can be reduced by a high Magic Defense stat or other protections against magic . Dark Valefor ' s Overdrive is Energy Blast , which deals around 50 , 000 damage regardless of stats . Unlike the other Dark Aeon s , Dark Valefor cannot break the 9999 damage limit except with Energy Blast , which always deals 47 , 136 to 53 , 225 damage , and cannot be reduced with anything but another aeon ' s Shield . Strategy . It is best to use Auto - Life , or summon an aeon when Dark Valefor ' s Overdrive gauge is full to take the blow . Dark Valefor can be defeated quickly , before she causes trouble . The party should have high Agility and Luck . High Strength and Defense are also useful , but all stats should be well into three digits . Break Damage Limit is recommended ; Dark Valefor is also perhaps the one enemy where Break HP Limit provides more benefits than drawbacks due to her inability to exceed 9999 damage . Valefor ' s Overdrive gauge charges up quickly , so the party needs to be fast . If his Strength is high enough , Wakka can take Dark Valefor out with a single full volley of Attack Reels . Yuna can summon Anima and use her Overdrive Oblivion , or Tidus can use his Overdrive Blitz Ace or Slice & Dice to also severely damage Dark Valefor . As with any other enemy , Dark Valefor can be killed instantly by Yojimbo ' s Zanmato . Dark Valefor glitch . Sometimes in the International PS2 version , a glitch will occur and the game will crash on either the cutscene before or after the fight . If this glitch happens once , it will always happen in that save file , effectively preventing the player from ever fighting Penance , acquiring the Jecht ' s Sphere in Besaid Village , acquiring Valefor ' s Energy Blast Overdrive if not obtained on the first visit , and even from acquiring Anima ( and subsequently the Magus Sisters ) if the player did not get the temple treasure from Besaid at the beginning of the game . To bypass this glitch , one must simply open the PS2 CD tray while the scene that is supposed to freeze starts ( the scene will stop while the tray is open ) and then close it . The saved game editor FFXED is also capable of fixing a glitched save file . The Greatest Hits version partially fixes the glitch . A new game started on this version will never have the glitch ; however , the glitch will still occur when loading an already - glitched save . The PAL version fixes the glitch completely , even when loading a glitched save from the International version . By extension , this also means the glitch is fixed in the " HD Remaster " . Musical themes . Dark Valefor , together with Dark Anima and Dark Magus Sisters , are the only Dark Aeon battles where the random encounter battle theme plays .