Chaos Bahamut ( Final Fantasy XIII - 2 ) Chaos Bahamut appears in " Final Fantasy XIII - 2 " as a boss . It is an Eidolon incarnated by Caius Ballad . It first appears in the pregame tutorial , and later as a boss . Chaos Bahamut is considerably weaker in comparison to the three other Bahamut s that appear in the game , Amber Bahamut , Garnet Bahamut , and Jet Bahamut . Chaos Bahamut ' s main appearance is at the end of Academia 500 AF . Chaos Bahamut is also fought in the DLC episode . Battle . Valhalla - ? ? ? AF - ( prologue ) . When Chaos Bahamut ' s HP has dropped to 50 % , a cutscene will occur . The player must continue to fight until another cinematic action occurs . The second battle is still simple , but Chaos Bahamut ' s moves have changed since the first battle . War ' s Benediction can be used to heal and it also grants the Haste status . Megaflare can do major damage and Chaos Bahamut ' s moves that prevent the player from attacking it . During the battle , a cutscene will play but the player must continue fighting until his HP has dropped to zero . Strategy . It is recommended to use Lightning Strike to fill up the ATB gauge , as well as watching out for Chaos Bahamut ' s attacks . Ullr ' s Shield can be used to heal and gain two status boosts : Protect and Shell . Using Graviton Cores will allow the player to fill up the ATB bar and attack . Academia - 500 AF - . Chaos Bahamut has two forms . At first he simply hovers before using Metamorphosis , upon which he becomes a flying mechanical wyvern . In its normal form , it will use potentially crippling physical attacks to beat down the party in sets of two . After a small amount of time of using these attacks , he will change between forms and begin to use powerful magic attacks instead , such as Megaflare , which causes a large amount of non - elemental damage with a side effect of wounding the party . Chaos Bahamut is immune to the Sentinel ' s Provoke ability but is susceptible to three debuffs : Deprotect , Deshell , and Imperil . Strategy . The best way to counter Chaos Bahamut ' s onslaught of powerful attacks is to use the all - Sentinel paradigm , Tortoise , to minimize Megaflare ' s effect . As Chaos Bahamut is immune to the Sentinel ' s Provoke the player will have to heal more often . Unless the party is fairly strong , it will be a good idea to have a Sentinel in all paradigms to minimize damage over a wide area . It is recommended a good Medic is in at least one paradigm . Since Chaos Bahamut is susceptible to some debuffs a good Saboteur can take advantage of this weakness . Once the party boosts its chain bonus up significantly , Chaos Bahamut shouldn ' t take long to defeat . Valhalla - ? ? ? AF - ( " Requiem of the Goddess " ) . If the player defeats Caius fast enough in " Requiem of the Goddess " , Caius transforms into Chaos Bahamut and is fought in that form . Chaos Bahamut has the same abilities he has in his other battles , but in addition can use Resist Wind and Resist Lightning to change his vulnerabilities . When using Resist Wind , he will become invulnerable to Wind and physical attacks , and with Resist Lightning , will become immune to Lightning and magic attacks . The battle starts with Chaos Bahamut being in his normal form where he uses physical attacks and Whirlwind , Ignis , and Umbral Vise . After a while he transforms into his aerial form where his abilities vary depending on which resist is currently on . If he is under Resist Wind , he attacks only with Pulsar Burst , and if under Resist Lightning , he will only attack with Obliterating Breath . After being in aerial mode for a while he will use Megaflare and switch back to normal form and cycle will begin anew . Defeating the DLC ' s Chaos Bahamut with a five star rank with Lightning ' s level at 9 or lower nets Lightning in her Knight of Etro armor as a Paradigm Pack ally . Strategy . Chaos Bahamut changing his properties forces the player to use Mage and Shaman roles accordingly , because Mage uses Lightning - based magic attacks only and Shaman uses only Wind - based physical attacks . The key to victory is to pay close attention on his Resist - ability and use the correct role to drive up his chain gauge . Same applies when using Paladin . Ruin should be used when under Resist Wind and Attack when under Resist Lightning . When he switches to aerial form , it ' s important to keep an eye out for Megaflare , and when he is about to launch it , the player must quickly switch to Knight and use Immortality to survive .