Monster Arena The Monster Arena is a battle arena in " Final Fantasy X " , situated in the Calm Lands . The Monster Arena is used to store fiends caught during the game . This is done by defeating the monster while using weapons with the Capture special ability , which can only be purchased here . Lord Mi ' ihen founded the Monster Arena 800 years prior to " Final Fantasy X " as a training facility for the Crusaders . The owner of the Monster Arena in " Final Fantasy X " is the unsent Trema , who has the unique ability to reconstitute pyreflies into fiends . In " Final Fantasy X - 2 " the Monster Arena becomes Clasko ' s Chocobo Ranch . Profile . Once the monsters are caught they can be battled at any time within the arena for a fee . If certain conditions are met new creations are bred and can be fought . As new monsters are bred , the owner rewards the party with special , and often rare , items . For each new creation the first battle is free , but any fight after costs . The most expensive battle is against Nemesis , costing 25 , 000 gil each time . Within the arena , the player cannot get a Game Over after defeat : they simply return to the entrance and can heal , and then try again . If the player has 8 , 000 gil or more they can fight Fenrir for free ; no matter what the result is , the player won ' t lose any money . A lot of the Monster Arena monsters ' equipment drops are semi - fixed . Some monsters , including all original creations except Neslug , drop equipment that provides a 6 % critical hit chance bonus instead of the usual 3 % ( this is relevant to weapons and armors , but only to attacks that deal physical damage ) . Monster directory . In the monster directory there are 13 different sections . These are the different areas in which monsters can be found . The areas and monsters in them are shown below . Some monsters appear in more than one area , but for capturing purposes they count towards the same area regardless of where they were found . For example , a Nidhogg captured on Mt . Gagazet still counts towards Cavern of the Stolen Fayth . In most ( but not all ) such cases , the fiend counts towards the first area where it can appear . Mi ' ihen Highroad . The following fiends also appear in Mi ' ihen Highroad , but count towards other areas for capturing purposes : Djose Road . The following fiends also appear in Djose , but count towards other areas for capturing purposes : Stolen Fayth Cavern . This category is called " Sunken Cave " in English language releases prior to the HD version . The following fiends also appear in Stolen Fayth Cavern , but count towards other areas for capturing purposes : Mt . Gagazet . The following fiends also appear on Mt . Gagazet , but count towards other areas for capturing purposes : Inside Sin . The following fiends also appear Inside Sin , but count towards other areas for capturing purposes : Omega Dungeon . The following fiends also appear in Omega Ruins , but count towards other areas for capturing purposes : Special monsters . Once certain requirements have been met new monsters can be unlocked . There are three extra groups in which the unlocked monsters are in : Musical themes . The theme that plays at the Monster Arena is called " Bravely Forward " . In the music player of " Final Fantasy VI Advance " , the last track of the list called " Fanfare 2 " is a remix of " Bravely Forward " .