Cie’th (シ骸, Shi-gai?, lit. “Cie Corpses”) [siːθ] is a term from Final Fantasy XIII and Final Fantasy XIII-2.

It refers to one of the two states that fall to a l’Cie; specifically to those who failed to complete their Focus in time. There are two types of Cie’th: Pulse Cie’th and Sanctum Cie’th. Pulse Cie’th appear more rugged and morbid, while the Sanctum Cie’th appear more smooth and crystalline.

Appearance and Personality
The Cie’th are best recognized by their crystallized and deformed appearance. While most of them are humanoid, a few of them are more monstrous. They do have a sort of hand/arm motif associated to them, as most of their most notable protrusions are or resemble deformed arms, with some of them having a pair of hands covering where their “eyes” should be. Most Cie’th have no emotions, intelligence, or goals, they just live trapped inside their crystallized bodies. They have long claws instead of hands, but they retain the facial features of their past selves. A pulsating red light in their chest keeps them alive.

The fal’Cie who created them also seem to influence the appearance that the Cie’th become. The Cie’th of Gran Pulse fal’Cie have what appears to be black, rough crystals formed all over their body, while the Cie’th of Barthandelus, a Cocoon fal’Cie, have mostly smooth, white crystals formed along their body.

The Cie’th are the non-sentient remains of a former l’Cie. They move purely on instinct and are known to be hostile towards living beings, including their former friends, which makes them widely feared as they also can wield magic. This is specially true to The Undying, a group of Cie’th whose hatred towards their former fal’Cie masters has made them all the more dangerous.

Only when they turn into Cie’th Stones do they show some of their former human selves, mostly their regret of failing their Focus and asking somebody to complete them in their stead so they can rest in peace.

Profile

A l’Cie, when chosen by the fal’Cie, is marked with an incomplete brand; a tattoo-like inscription, when given a Focus. The brand completes itself over time, working as a timer for the l’Cie to complete their Focus. Should the l’Cie fail, or the time runs out, the l’Cie loses their humanity and crystals cover and twist their body. Their heart is sealed in endless despair, a fate far more torturous than death.

It is said the rate at which a l’Cie becomes a Cie’th depends on their psychological state; the more panicked and distressed a l’Cie is while completing their Focus, the faster they will turn into a Cie’th. Fang reveals that as time runs out, the Pulse l’Cie mark sprouts more and more arrows and eventually an eye, and when the eye is fully opened, they are transformed.

Fal’Cie can transform humans instantaneously into Cie’th by assigning them no Focus at all, as shown by the Cavalry soldiers all transforming into Sacrifice Cie’th on the way to Orphan’s Cradle. After the Day of Ragnarok, the Cie’th become scarce over time, although in one future in the year 400 AF, the Proto fal’Cie Adam uses Cie’th as its enforcers to wipe out any opposition to it.

Cie’th Stones

Main article: Cie’th Stone

It is possible for Cie’th to still complete their Focus, in which case they would still transform into crystals. Over the course of years, the energy of a Cie’th may dry out, in which case it would turn into a crystalline tombstone, unable to move about but gaining the ability to communicate and ask others to complete their Focus for them. These Cie’th Stones can be found in abundance throughout Gran Pulse.

The Undying

Main article: Undying (Final Fantasy XIII)

There is a powerful group of Cie’th known as The Undying, who have a unique appearance compared to the other Cie’th. These Cie’th defy the will of the fal’Cie that made them into l’Cie and are filled with hatred because of it toward everything that lives. In Final Fantasy XIII completing a mission which has one of these Cie’th as a mark normally allows the player to access a previously closed-off area, except for the first and last marks, which initiate and finish the series respectively.