Chaos (Final Fantasy XIII)

Chaos is a matter in the Fabula Nova Crystallis mythos which comes from Valhalla. It is the blessing Etro granted to mankind, but is also dangerous in the fact that 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.

Datalog
''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.''
 * Yeul's Confessions

''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.''

Background
Chaos appears as black smoke-like substance. Monsters defeated in battle in Final Fantasy XIII-2 disperse into chaos, unless they are captured, in which case they transform into a crystal.

It is never specified how chaos came into being, and whether it is a natural part of the universe that has always existed, or if it is something born out of an imbalance between the Visible and Invisible Worlds, a concept that is mentioned in the official Fabula Nova Crystallis mythology.

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 Invisible World by the time Etro entered the realm 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. This act, giving humanity a "heart", restored the world balance while Etro held the rest of chaos under her control within Valhalla.

Final Fantasy XIII-2


Due to Etro's intervention in releasing Lightning and the other Cocoon and Gran Pulse l'Cie from their crystal stasis, chaos seeped out of Etro's Gate. Etro reversed time and sealed the chaos back in Valhalla, but Lightning, who had been caught by the chaos, was dragged into the Historia Crux and taken to Valhalla.

As a result of Etro's intervention on the Day of Ragnarok, Lightning's sister, Serah Farron, was 'blessed' with numerous abilities. Aside from learning magic after moving to Pulse, she gained the ability to use Time Gates, and capture monsters and have them aid her in battle. Serah also gained the "Eyes of Etro", which enable 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 perform an Incarnate Summoning (essentially transforming himself into Bahamut) to protect the seeress Yeul. This granted him immortality along with the ability to Incarnate Summon at will, and become Chaos Bahamut. It 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 pleased.

Caius' goal is to kill Etro to allow chaos to consume all of time, turning the world into Valhalla. When he is defeated by Noel, the Heart of Chaos is destroyed, resulting in Etro's death. This causes the chaos to burst from Valhalla without restraint as it consumes Gran Pulse, melding the two worlds into one: Nova Chrysalia.

Lightning Returns: Final Fantasy XIII


By the time of the game's events (1000 AF), the last surviving part of Nova Chrysalia floats in the Sea of Chaos. Chaos flows through every part the world, with the most heavily effected being the Wildlands, as that is where Etro's Temple, the source of the Chaos, is located. Occasional nocturnal outbursts of the energy, called Chaos Infusions, occur within cities which summon powerful monsters.

One of its most noticeable effects is causing people not to be able to age or die naturally, and causing children not to be born. It has also created heavy burdens of varying sorts on people's hearts, which is the main reason the deity Bhunivelze must send the Savior on her mission to free the people from their burdens. There are also people in the world who appear to have a deep affinity with Chaos: Lumina is shown to have this affinity, as she is seen walking through it unharmed and summoning monsters from it; Snow Villiers is also seen absorbing Chaos into his branded arm when he destroys monsters spawned from it.

Trivia

 * In Final Fantasy XIII, when Oerba Yun Fang summons Bahamut at the beginning of Chapter 11., black mist, resembling chaos from Final Fantasy XIII-2, appears and Bahamut emerges from it. Also, it seems this concept was used while choosing an Eidolon for Caius.
 * Also present in Final Fantasy XIII, when Attacus uses Meditate, black wisps of mist are drawn into its blade. These wisps seem to be chaos.
 * Chaos in Final Fantasy XIII-2, having always existed, is perhaps comparable to the elemental force '' found in Greek mythology, where Chaos had always been present since the beginning of the universe.
 * In terms of its effects on the Visible World, chaos is similar to the Void from many Final Fantasy entries.