Omega Ruins The Omega Ruins , also known as Omega Dungeon in the menu at the Monster Arena , is a large dungeon located within a small group of islands to the east of Spira ' s main continent in " Final Fantasy X " . Rather maze - like , like Inside Sin , this place must be mapped by the player . Navigating the dark passages , Tidus and his friends will encounter some of the toughest fiends in the game , including the Master Tonberry and Great Malboro , while also coming across chests , which yield some handy ( albeit random ) treasures . At the end of the cave , two deadly boss es await the party ' s arrival . A traitor to Yevon , Omega , was executed for treason centuries ago , his malicious spirit still haunting these ruins . His hatred has turned him into the fiendish Omega Weapon . His hatred for Yevon was so strong , he also spawned a lesser Weapon : Ultima . Coordinates . To be unlocked on the airship map , the coordinates 69 - 75x and 33 - 38y have to be found using the search function . Items . The treasures are randomly either a treasure or a Mimic . If the treasure is a Mimic , the nearby chests disappear . If one opens a chest but leaves the chest group , the other chests will disappear even if the Mimic did not appear . The goal is to avoid a Mimic in all four groups to earn 99 Warp Spheres . The only way to get 99 Warp Spheres is to save the game before entering for the first time due to " RNG " ( random number generator ) function , which is not actually random , and not exclusively at the whim of the " random " factors set in - game at Load or by the console . Upon landing at the ruins , the " odds " are set on whether players can succeed at opening every chest , or not ( 1 chance for success possible in 240 attempts , without guarantee ) . Saving ( anywhere ) after visiting Omega Ruins locks in those odds . Once set , they cannot be changed thereafter for that playthrough . The exception is the PS4 and PC HD remake versions , where players can reroll to get the 99 Warp Spheres by using the save in the ruins . However , loading a saved game with any of the chests open resets the prize counter , and the player still needs to open all 12 chests in a row to get the 99 Warp Spheres . Saving the game between groups does not reset the counter ( i . e . opening 2 chests , saving , then opening the 3rd chest still gives Turnover as expected ) . Should one pick wrongly along the way and encounter a Mimic , the player should do a soft reset by reloading the file save and try again . The " timing of opening chests " or " the order in which the player open the chests " , do not influence the chance to get 99 Warp Spheres . It is recommended to use the diagram to get the Teleport Sphere by activating the glyphs . For that , the player must move to the west corridor from the entrance , follow the path up to a doormat glyph on the wall , head north to find a chamber with four chests , head northwest into a side corridor with another glyph , activate it , and return to the " doormat " one . The glyph is now working and it raises a bridge out to a chest suspended above the central stage . The chests contain the following items : These are the normal treasure chests : Musical themes . The theme that plays in the exterior of the Omega Ruins is " Beyond the Darkness " . " Gloom " plays while in the Ruins .