Chaos ( Final Fantasy XIII ) Chaos ( or ) is a matter in the mythos which comes from Valhalla . Chaos is the blessing Etro granted mankind in the form of hearts , but is also dangerous because if unbound , it would turn the physical world into a timeless realm . According to legends , those who can harness their inner chaos can time travel , control monsters , and have visions of the future . The term is capitalized in " " , but not in " Final Fantasy XIII - 2 " , despite the terms referring to the same substance . In " Final Fantasy XIII - 2 " , the Japanese term for chaos is written in katakana , but in " Lightning Returns : Final Fantasy XIII " , the the term is changed to with the furigana reading of " kaosu " . Datalog . " Final Fantasy XIII - 2 " . " The chaos of the unseen realm is a malevolent energy that seeps through into the world of mortals . The existence - defying darkness witnessed by Lightning is an immense and inexorable force , a creeping doom that she is not even certain acts with a unified purpose or will . " " Where the chaos of Valhalla leaks into the mortal realm , the laws of the physical world are undone . This paradoxical energy seeks to return all existence to the unseen realm , but at times it seems to show an almost affection for those who share an affinity with chaos . " " Our bodies are made of the blood of the goddess . Our souls are formed of the chaos which she bestowed upon us . The Farseers were an ancient people who embraced the chaos more than any other . They were Pulse ' s oldest tribe , and I was their seeress . " " The power to see the future . The power to travel the timeline . The power to bend monsters to your will . The power to remember in your dreams , even when the timeline has changed . They are manifestations of hidden chaos , and in a chosen few , these powers are great indeed . Such are the blessings of the goddess . " " The unseen Chaos is the darkness which dragged Lightning into Valhalla . Five hundred years ago , the border between Valhalla and this world was broken open , and the world was flooded by an ocean of Chaos . " " When Lightning came into contact with the unseen Chaos , she touched a darkness that should never exist in the human world . Etro had dammed the unseen Chaos in her temple , but when she died , there was no one left who could stop the catastrophe that later ensued . " " If the unseen Chaos were to flood into the world again , it would threaten God ' s plans for humanity . It is said that a " great Chaos " lies within the temple of the goddess in the Wildlands — the parallels to the unseen Chaos of Valhalla are too close for comfort . " Profile . Chaos is black smoke - like substance . Monsters defeated in battle in " Final Fantasy XIII - 2 " disperse into chaos , unless captured , in which case they transform into a crystal . In a fragment entry " Bhunivelze ' s Sleep " it is said the physical world contains within its form endless chaos . Chaos had already manifested in the unseen realm by the time Etro arrived and met Mwynn in her final moments . Taking Mwynn ' s place as protector of the world balance , Etro placed a piece of chaos inside each human giving humanity a " heart , " restoring the world balance while Etro held the rest of chaos under her control within Valhalla . The English localizations make no distinction between hearts and souls , but the two are separate entities in the Japanese version , albeit linked . Mythology . Chaos first manifested as a result of Bhunivelze ' s attempts to reach the unseen realm where his mother Mwynn resided . To find the Door of Souls to reach the unseen realm , Bhunivelze created Pulse , Etro , and Lindzei to perform the task , but discarded Etro . Yearning for Bhunivelze ' s attention she tore herself apart and disappeared into the unseen realm where she met Mwynn as she was being consumed by chaos . With her last breath , Mwynn tasked Etro with protecting the balance between the visible and unseen realms . While not fully understanding what Mwynn had asked of her , Etro ' s desire for company in the humans that were created from her blood inspired her to place a piece of chaos within each human being to give them " hearts . " A cycle is established where the souls of deceased humans enter Valhalla and sink into the sea of chaos . The heart dies while the soul from inside the heart is eventually sent back and reborn in a new form with a new heart . A piece of chaos is placed within each newborn life keeping the level of chaos constant . The only exception is Paddra Nsu - Yeul , whose cycle of reincarnation kept her chaos within the mortal world with disastrous results , as each rebirth splintered her soul adding into the chaos festering between the two realms . Story . " Final Fantasy XIII - 2 " . Due to Etro ' s intervention in releasing Lightning and the other l ' Cie from their crystal stasis on the Day of Ragnarok , the chaos compromising Yeul ' s past lives erupted as a result of the timeline being altered . Though Etro reversed the process , the chaos dragged Lightning into the Historia Crux and she ended up in Valhalla and Lightning ' s sister , Serah Farron , was ' blessed ' with numerous abilities ; aside from learning magic , gaining the ability to use Time Gate s , and capture monsters and have them aid her in battle , Serah gained the " Eyes of Etro , " which enables her to see changes in the timeline , but it doubles as a curse as it gradually shortens her lifespan . Caius Ballad possesses the Heart of Chaos , said to be Etro ' s own heart , as a result of the goddess resurrecting him after he sacrificed his life to protect the seeress Yeul . The Heart of Chaos makes him immortal and grants him some affinity or control over the chaos of Valhalla , which may have allowed him to create the paradox effect and shape the timeline as he pleases . Caius ' s goal is to kill Etro to allow chaos consume all of time , turning the world into a timeless world like Valhalla to release Yeul from her cycle of reincarnation . When he is defeated by Noel , the Heart of Chaos is destroyed and Etro is killed . With nothing to hold it back , the chaos bursts from Valhalla and consumes Gran Pulse , melding the two worlds . " " . By 1000 AF , the last surviving part of the world is known as Nova Chrysalia . Chaos flows through every part the world , but its effect is the strongest in the Wildlands as this is where the Temple of the Goddess , the source of the Chaos , is located . Occasional outbursts of the energy , called Chaos infusion s , summon powerful monsters and leave behind soul seeds . Some people have remained unaffected by the Chaos and continue to age through unknown means . The fal ' Cie Pandaemonium produces food for the world out of Chaos , but some people prefer not to eat it and grow their own food . With Etro ' s death , the life cycle is broken and humans have become biologically immortal yet unable to bear children . As revealed in " " , the Academy was set up to analyze the Chaos to find a way to reverse its effects . While the populace settled on Nova Chrysalia some scientists remained on the manmade Cocoon to continue secret research into Chaos , discovering that Antimatter Manipulation Principle technology can control it . The research into this was never completed as the researchers disappeared . Though not directly stated , it may be that the Ark of the manmade Cocoon was where the research took place , and utilizes AMP technology to control the Chaos and halt the flow of time . Chaos has created heavy burdens of varying sorts in people ' s hearts , which is the main reason the deity Bhunivelze must send the savior to free the people from their burdens . In cases like Snow Villiers , due to his l ' Cie status , absorbing Chaos can have mutative effects . Lumina and Caius have a special affinity with Chaos : Lumina uses Chaos to create a physical form for herself , and gains the ability to summon and control monsters from it , while Caius has completely melded into Chaos after his defeat by Noel and Serah , and can thus utilize its full power . Despite the desires of their final incarnation , their symbiosis with Chaos forced the Yeul incarnations to consider remaining in the dying world as to not jeopardize the new world that will be born after Nova Chrysalia is destroyed . When Lightning visits the Temple of the Goddess , meets the Yeuls and battles Caius , she learns the truth behind the force known as the " great Chaos " said to reside in the temple : It is made up of the very substance of Yeul ' s souls that over generations of rebirth have become threaded together to form the fabric of the Chaos . Yeul herself says that the Chaos is her love of Caius . When the Apocalypse begins , the final incarnation of Yeul is allowed to depart for the new world with Noel , and the Chaos is sucked into a new unseen realm with Caius and the past incarnations of Yeul holding it at bay and overseeing the cycle of life in Etro ' s place . A new cycle of life is established where the deceased pass on to the unseen realm and are guided by Caius and the Yeuls into the Sea of Chaos from where the soul can be reborn . Musical themes . " Chaos " is the fifth track on the first disc of " " . It plays during the boss battle against Zaltys in Yusnaan during the introductory mission . The part between 2 : 33 to 4 : 41 plays during certain battles when the battle lasts for a while or the enemy was Staggered certain number of times . " Chaos " also appears as one of Battle Music Sequence s in " Theatrhythm Final Fantasy Curtain Call " for " Lightning Returns : Final Fantasy XIII " . Etymology . This is congruent with the " Final Fantasy XIII " lore where it appears chaos flows from the immaterial world , associated as being the Void in the " Final Fantasy " multiverse .