Akuma

An Akuma is the demon equivalent of a soul. Akuma usually appear as key-shaped necklaces.

Appearance
Akuma's take the form of small, silver, key shaped locket that is hung on a long chain around the demon's neck. There is a shape on top of the key's blade that varies between demons. Supposedly, no two are the same.

Overview
Demons are "born" with this locket around their necks and are unable to take it off without breaking the chain. Breaking the chain means that the demon will be temporarily detached from his/her Akuma. The Akuma will then go inside the demon's body, and burst out from inbetween the shoulder blades in the form of a flame-like wing. This is known as "Unraveling." The colour and shape of the Akuma when in this form depends on the demon's personality, IQ and strength. Also, their eye colour will always be featured in the colour scheme of their Akuma when they Unravel. If a demon breaks the chain of their Akuma when in necklace form, they will go into their true form. They can only survive in this form for around a minute before returning to normal. It is taboo to touch another demon's Akuma. It is unknown exactly what happens if a demon touches another's Akuma, due to a lack of knowledge passed down through the family. But what is known is that if the Akuma is shattered, the demon will die. There are only two ways to break an Akuma, (in necklace or wing form) either by coming into contact with the Pendant of Dragonia, or being cut with White Rune katana of the lasting sun. Demons are all in all very sub-conscious about anybody interacting with their Akuma in any way. It is considered incredibly rude to even look at a demon's Akuma. Demon's hardly ever touch their own Akuma, but doing so signifies that they feel great emotion. (Which is unusual for a demon) This also makes them Unravel, but without going into their true form.

Night Shadowsoul
When Night's Akuma is in it's necklace form, it is described as dull and worn. This mirrors Night's unfortunate past of being physically abused by his father for not agreeing with his ideals. The shape that is on top of the key's blade is a heart. This references Night's kind and loving heart and the ability to realize that what he was being told to do by his father is wrong. When Night Unravels, his Akuma appears as a black blade of spiked yet soft daggers that spread out like a hand fan. It can also twist and turn to an extent. His Akuma seems to shed feathers, or at least, something that looks like feathers. There are many small golden sparks that float around his Akuma, and follow that movement of it.

Raven Shadowsoul
Raven's Akuma is bright yet worn. This shows that Raven is a confident person who want's to succeed, yet is damaged somehow. This most likely refers to her insanity. Raven's shape is a star. Stars symbolize achievement and authority, like how Raven is the older sibling who, despite not being chosen, ended up being the heir to the Dark Lord. When Raven Unravels, her Akuma turns into a pink flame with three small, thin black tentacles. There are several circular black and pink beams that pulse individually.

The Dark Lord
The Dark Lord's Akuma is described as dark and lightly scratched. This could mean that he is a shady person who doesn't care about hurting other people. His shape is a triangle. Triangles are said to represent change, like how the next generation after him (Raven and Night) are very different from how demons normally act and they both change the family bloodline forever. We do not see the Dark Lord Unravel, but we can at least assume that his Akuma would be black and red.

Trivia

 * Night's Akuma is identical to a necklace owned by the author.
 * When the the author did the first sketch of Night, she added in the necklace to make his character design look more interesting. It was only afterwards when the necklace was given a name and purpose.
 * For a short while, Akuma were called "Kokoro," which means "soul."
 * Akuma means "Demon" in Japanese.