Akuma

Akuma (アクマ, Akuma; Literally meaning "Demon") are a staple of the anime/manga series D.Gray-man. They are creatures comprised of one or more human souls, metal skeletons and Dark Matter, the latter two supplied by the Millennium Earl. By design, they are forced to obey the orders of the Earl and the other members of the Noah Family without question, even if it is against their will. They, however, have been known to go behind the Clan's backs on occasions when they are unsupervised.

Overview
Akuma are created when a living human in mourning over the loss of a loved one makes a contract with the Earl to bring the soul of said lost loved one back. The Earl presents the living human with a skeleton of Dark Matter and has them call the departed soul of the loved one back, the soul then becoming trapped within the skeleton and forced to obey the Earl's will. Once trapped within the skeleton, the soul then "puts on" the body of the loved one who called it back, using their skin to move around in the human world in disguise.

After the transformation is complete, the Akuma, now a Level 1, the soul of which is tormented and consumed by hate for the living world, goes around killing in order to grow and evolve to become stronger and better serve the Earl's purpose.

Evolution
As they grow through killing humans, Akuma evolve, the known levels ranging from 1 to 4, with 4 being the strongest. Akuma can also merge to form sub-levels, such as the Giant Akuma.

Purification
Though there are various ways to kill Akuma, the souls trapped within them can only be purified by an Exorcist using an Anti-Akuma Weapon, or Innocence. If an Akuma is destroyed by anything other than Innocence (including self-destruction, cannibalism and destruction at the hands of a Third Exorcist), the soul trapped within the Dark Matter skeleton disintegrate along with the Dark Matter.

Skeleton
The initial form of an Akuma is that of the Dark Matter skeleton. Once a human says the name of the person they are trying to resurrect, the soul of that person is called back and trapped within the skeleton. As soon as the skeleton has a will, it is bound to the Earl's command, even if it is against the soul's will. Oddly, even if they had no knowledge of the Earl beforehand, the soul knows what has happened to it the moment it is implanted into the skeleton.

Level 1
Level 1 consists of a floating ball shaped creature with dozens of gun barrels protruding from it that fire large bullets. The gun barrels are flexible and can be bent to face any desired angle without affecting its firing capabilities.Level 1 Akuma appear to be able to fire beams of energy from an opening beneath their face. This attack is called "Akuma Cannon" by the Earl. The souls inside a Level 1 Akuma have the bodies and clothes of their original forms. However, their faces are rather distorted and there is a chain around their necks expressing the intense pain and sadness of the trapped soul.

Level 1 Akuma exhibit something of a transition from the deterioration of their human personality into an evil personality for level 2 later on as observed in their increasing obsession to simply kill and may, hence, show zombie-like behaviour in their human form. A Level 1 Akuma will advance to a Level 2 once it has fulfilled a substantial quota of kills of humans and exorcists.

Level 1.5
Level 1.5 is not an actual level per se, but more of a mid-way point for a Level 1 Akuma. The only difference is that the Akuma becomes rounder and more spherical, with the ends of the barrels on the surface. Their facial expressions appears to show more instances of emotions closing in to a personality as of a Level 2 (in the anime, a level 1.5 Akuma grins like a maniac when it successfully anticipates and counters Allen Walker's attack from behind a building). Their bullets can also penetrate barriers that normal Level 1 Akuma bullets can't.

Level 2
Level 2 produces a dramatic change. They develop a unique ability and a sense of self. Level 2 Akuma are capable of intelligent thought and are largely independent, though they still maintain unquestionable loyalty to the Millennium Earl and the Clan of Noah. However, it has been shown that they have the ability to ignore or postpone a direct order or reject a mission in favour of their own priorities. The souls of Level 2 Akuma seem to become more deteriorated. The souls inside of these Akuma can't seem to be identified at all and are in a fetal position, wrapped from head to toe in bandages. Level two Akuma are known to have the face of a Level 1 Akuma in their vital areas such as the head or chest most of the time.

Level 2 Akuma come in all shapes and sizes (some have even appeared simply as a gas, fire, dolls, a demonic court jester, even a playing card, and they especially take form of animals) and they have no common appearance. Thus far, Level 2 is the only state in evolution where appearance is varied as 1, 3, and 4 all maintain the same shape with only subtle differences. They also have different powers, such as copying a person's appearance (mirror image), emitting "ice fire" which hurts worse than normal fire, creating blades of air, emitting destructive sound waves, and creating bubbles that absorb water from everything they touch. Some Level 2 Akuma even carry modern day weaponry such as homing missiles and various types of firearms that resemble machine guns and so on, as observed in the manga. After murdering enough people, it can evolve to Level 3.

Level 2.3
In the anime three level 2 Akumas fuse together to make a stronger one. Well, not so much a fusion as an absorption. The strongest of the three, angered by her teammates' incompetence, absorbs them into herself to get stronger. In the new form they are larger, stronger, and added fire power. However, their weakness was their poor mobility; being large and disproportionate, they couldn't move so well. Their fire power, though strong, was not enough to keep all their enemies at a distance, making it a sitting duck, and leading to their defeat.

Level 3
Level 3 brings perhaps the most terrifying changes of any previous stage. Regardless of their appearance in Level 2, all level 3 Akuma become bipedal, roughly 8 to 9 feet tall, with sharp jagged teeth, and wear what looks like medieval armor that covers most of their bodies. Their Level 1 face (the one like a human face) is under the mask they wear, shown when Lenalee was up against Eishii and when she destroyed him the mask deteriorated and showed the Level 1 face. The only difference between each other is the colour of their armour and the helmet design of each one is unique. In addition to this, they receive a massive power boost.

A Level 3 Akuma is easily capable of standing up to multiple Exorcists in combat and usually has an extremely powerful ability in addition to its greatly improved strength and speed. They have also been shown to cannibalize their fellow Akuma, such as the killing of Kawamura and capturing Chomesuke, attempting to eat her. Their abilities seem to revolve around the use of Dark Matter, the polar opposite of Innocence. The souls embedded in the Level 3 Akuma are near gone and appear as a floating dark mass with eyes. Before Edo, the appearance of a Level 3 was rare with most of them being stationed in Edo and isolated from the rest of the world. As the Exorcists grew stronger though, the Earl was forced to turn to more powerful Akuma to bring them down.

Further, Level 3 Akuma appear to be separated into 'types', as Eshi stated he is a 'close-combat' type. the exact number of types and their specific effects on the Akuma's power is uncertain, but it can be guessed that close-combat types like Eshi are one's whose ability is not used directly for fighting. For example, Eshi, who is a close-combat type, has an ability that increases gravity on anything he strikes, but this ability cannot directly injure and kill, and because of that, his physical strength and durability are increased to compensate. On the other hand, the Level 3 that Allen Walker first fought can be considered as more of an 'ability-oriented' type, where the Akuma's ability to break down matter, unlike Eshi's ability, can be used to wound and kill a target. It would stand to reason then that Level 3 Akuma who are 'ability-oriented' don't have as much physical strength and less durable bodies and can be more easily injured than close-combat types like Eshi.

Giant Akuma
During the fight at Edo, The Earl revealed that a mass number of Level 3s can fuse together to create Giant Akuma. Due to their gigantic size they are slow but have long arms and legs to attack directly but their movement is awkward and easy to dodge if paying attention. Their skin is also very durable making it hard for an average Exorcist to do any damage to them. They can also perform an attack known as Evil Star Gita which fires rapid beams at any and all directions.

While still a high risk opponent, they seem to lack much of any ability to think for themselves and are generally seen taking orders from the Earl or a Noah. Bookman has commented on this, and upon seeing them fuse at Edo, has stated that "The idiot machines have simply combined to make a bigger idiot machine".

Level 4
Level 4 is the most powerful and destructive Akuma known to the Exorcists so far, surpassing even the strength of the Noahs. Despite its immense strength, like all other levels of Akuma, the Level 4 still has to obey the Noah clan, though they no longer have to obey the Skulls, unlike the Level 3.

The transformation from a Level 3 seems to be much more visceral than any other seen thus far. The qualifications for the evolution are not known. The first Level 4 seemed to come out from the eye of a Giant Akuma that was defeated by Winters Socalo, probably after merging with the bodies of other akumas that were destroyed. The Level 3 seems to meld into a gruesome amalgamation of limbs and "flesh". From this a "shell" was sprouted of a woman with a horrifically bloated stomach(notably with the number 4 displayed on it), from which the Akuma bursts from.

The Akuma takes the form of a child-like creature with a bloated stomach. There is a black star on the Akuma's stomach and a little, closed-ring, "halo-like" oval above its head and wings on its back ironically making it, the strongest living weapon thus far, look like a childish, demonic angel. The remnants of the human soul, though not seen by the viewer, is apparently such a grotesque state that Allen Walker needed to vomit from just a glance of it. The difference of power between a Level 3 and a Level 4 is gargantuan, to the point that a single one of them was capable of destroying a large portion of the 5th Laboratory, incapacitate the five generals, fight and overpower Allen Walker (who by the time had surpassed the critical point) and Lenale Lee, surviving the combined attack of the former and Cross Marian and even after that, had enough energy to attempt an escape.

The Earl has also implied that the Level 4 is a stepping stone to something even more terrifying, though it has not been clear to what he has meant by that yet.

Powers and abilities
Poisonous Blood: The blood of Akuma, known as Akuma Oil, is rich with Dark Matter, making it poisonous to humans. Skin-to-skin contact and inhalation can result in humans, at the worst, contracting a deadly virus that makes pentacles appear on the skin, starting at the contraction site, before it spreads out, solidifies the body, and ends in the infect breaking down. At its mildest, it can result in fevers, illness and difficulty breathing. The effect of the virus is lessened for parasite-type Exorcists, who can purify the virus within their body. Individual Techniques: Level 2 and Level 3 Akuma are shown to develop their own unique abilities, fueled by the Dark Matter in their bodies.
 * Blood Bullet: The signature skill of Level 1 Akuma and an optional ability for Level 4, Akuma can mold their blood into bullets and fire them at targets, a successful hit resulting in an immediate spread of the Akuma blood virus through the target's system and a quick death if the situation is not remedied.
 * Toxic Gas: When bodies of Akuma and those killed by the Akuma blood virus are left to fester, their blood sublimates and leaves a noxious gas in the air that can be fatal if inhaled too much.

Akuma Scream: An ability unique to Level 4 Akuma, they are able to release a scream powerful enough to paralyze every living thing in a wide radius with tremendous amounts of pain and, even after the scream is finished, leave the victims too dizzy to move and, in the case of Exorcists, synchronize with their Innocence.

Noteworthy Akuma

 * Pierrot
 * Eliade
 * Eshi
 * Chomesuke
 * Alma Karma
 * Mimi
 * Nalei

Third Exorcists
Third Exorcists are humans who have had cells from the body of Alma Karma, whose regenerative core allowed for him to survive the implantation of a shard of an Akuma Egg and who mutated in an Akuma-like creature, himself, implanted in their left arms. These cells allow them to turn their left arms into Akuma-like appendages, which they use as weapons against Akuma by turning the Akuma's ability to cannibalize their fellows against them.

Like regular Akuma, Third Exorcists have an Akuma presence that is registered by Allen Walker's Pentacle Eye, and when their arms cannibalize Akuma the process also destroys the human soul bound to the Akuma's body.