Hecatoncheir ( summon ) Hecatoncheir is Vanille ' s Eidolon in " Final Fantasy XIII " . It is an earth - elemental creature with multiple arms . Hecatoncheir ' s summon ability is Gaian Salvo . The writing on Hecatoncheir and his summon symbol reads : Story . " Final Fantasy XIII " . Fang becomes suspicious that Vanille is hiding something from her , and confronts Vanille about their past . To get the truth out of her , Fang lies and says that she remembers the events surrounding their original Focus . She claims she was the one who became Ragnarok and scarred Cocoon many centuries ago in the War of Transgression , not Vanille . Although Vanille knows the truth , she tries to deny it . As if to punish her for twisting the truth and put an end to her lies , Hecatoncheir is summoned by Vanille ' s distress . Fang interprets this as a sign of truth and Vanille admits that Fang was the one who transformed into Ragnarok and laid waste to Cocoon . After the battle Vanille breaks down into tears , saying she did not want Fang to bear the guilt of the beast ' s bloody rampage , and Fang forgives her . Vanille rides Hecatoncheir in Gestalt Mode when the party returns to Cocoon and emerge out of a gate above Eden , crashing a grand prix . " " . When Lightning calls for help the Eidolons , along with her former friends and allies , they answer , and aid her in defeating Bhunivelze . As the souls of humanity travel to the new world born after Nova Chrysalia ' s destruction , the Eidolons bid farewell to their old companions before fading away . Gameplay . Boss . Vanille and Fang first face Hecatoncheir as a boss in Mah ' habara Subterra , as a test to prove Vanille ' s strength to him . Hecatoncheir is the last Eidolon fought in the game . Summon . Hecatoncheir is Earth - elemental and the only Eidolon with the Quake ability . He is the only Eidolon that does not have Curaga , meaning Vanille must heal for herself . Vanille ' s Gestalt Gauge increases by driving up enemy chain gauges , inflicting and removing status ailments and restoring HP . In Gestalt Mode , Hecatoncheir transforms into a Magitek Armor , quadrupedal mech with four machine gun turrets that Vanille can ride . Hecatoncheir ' s gameplay concept is Shooting Blaster , and its Gestalt Mode attacks are ranged and place an emphasis on the enemies ' positions in the battle . Hecatoncheir ignores physical and magical defense and , despite not having a name for the ability , such as Penetration used by Odin , Shiva , and Brynhildr , possesses an attribute which similarly reduces all resistance and immunity to elements to no resistance . Other appearances . " Final Fantasy Legends II " . Hecatoncheir appears as an high - ranked earth - elemental summon for the player to use . The summon ' s design is based off its appearance from " Final Fantasy XIII " . Hecatoncheir ' s special ability is Gaian Salvo which deals earth - elemental damage to all enemies . Summoning Hecatoncheir costs 3 points from the Consumption Gauge . Depending on the summon ' s type and rank , the user is able to learn the following abilities : " Dissidia 012 Final Fantasy " . Hecatoncheir appears as a summon in " Dissidia 012 Final Fantasy " . When summoned it uses Gaian Salvo to turn the stage bravery to zero . He takes the appearance from his concept artwork . He can be purchased from the secret Moogle Shop within the Land of Discord during Scenario 000 for 1 , 000 KP . " Mobius Final Fantasy " . Hecatoncheir appears as an ability card and as an enemy boss during the " Final Fantasy XIII " collaboration event . " Final Fantasy Trading Card Game " . Hecatoncheir in his Gestalt Mode render appears in " Final Fantasy Trading Card Game " . Its cards are earth - elemental . " Triple Triad " . Hecatoncheir appears on " Triple Triad " cards in the version available via " Final Fantasy Portal App " . Non - " Final Fantasy " appearances . " Guardian Cross " . Hecatoncheir appears as an obtainable card .