Akuma

Akuma (アクマ, Akuma lit. demon) take up the majority of the Earl's army and serve as the "foot soldiers". When one is mourning for a lost relative or friend, the Earl appears offering to resurrect that member for them. However, the raised soul becomes the power source for the Earl's weapon and must obey his orders. The Noah Family has also absolute control over the Akuma, regardless of their levels.

In contrast, a Akuma "converted" by Cross can resist orders from the Earl for a limited amount of time. Akuma "wear" the skin of the one who resurrected them. They use this to blend in, as Exorcists cannot tell Akuma from human with the exception of Allen.

The Akuma share a metal core made of dark matter that resembles a simplified human skeleton. Their blood also contains a blood virus, which rapidly travels through the victim's body, marking it with pentacles. The virus can be spread by blood bullets of a high caliber shot by the level one Akuma. Eventually, the body crumbles into dust and gives off a poisonous gas. However, parasitic Innocence users can force the virus to recede and nullify it, giving them a near immunity resistance. In fact, Baron Arystar Krory III drinks them by flasks to gain power boosts, but overdose does render him vulnerable to the poison. The Noah Family members are also immune to the poison, as Jasdevi drank an entire flask of Chomesuke's blood with no ill effect, aside from the urge of vomiting in disgust.

The Akuma evolve into higher levels, gaining strength as they do so, with level four being the highest seen so far. Each level Akuma becomes more humanoid than the level before it. As its evolution continues, the embedded soul deteriorates. An Akuma-producing plant, referred to as an "egg", is required to create Akuma. It has been stolen by the Exorcists and been destroyed, but the Earl is creating a new one. There is a special significance to the evolution of an Akuma, of which the Exorcists do not know, thinking they are mere killing machines, and the Earl wants to keep it that way. If destroyed by a force other than Innocence, the soul is consumed by dark matter and is destroyed.

Level 0
Level 0 is the Akuma right after being created. It is only the metal skeleton which is presented similarly to a model kit format when still unoccupied by a soul. The human soul is the dominant personality, but it is still bound to the Earl's control. The ends of the arms varies from Akuma to Akuma. The separate 'bones' are not connected in any way, but rather hover near where they would be connected. After a soul occupies the skeleton, a pentagon along with its host's name below it will be inscribed on the forehead of the skeletal structure. No matter how inhuman an Akuma becomes upon reaching level 2, the level 0 form remains as its skeleton.

Level 1
Level 1 consists of a floating ball shaped creature with dozens of gun barrels protruding from it that fire enlarged 5.56 x 45 mm NATO-like rounds. The gun barrels are flexible and can be bent to face any desired angle without affecting its firing capabilities. 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 intense pain and sadness of the trapped soul. Level 1 akuma exhibit somewhat a transition from deteriorating human personality to 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 exorcist.

Blood Bullet
The bullets shot by the Akuma contain a poisonous virus. The bullets made of the blood of the Akuma is deadly to the human flesh, spreading rapidly in the form of pentacles (dark purple stars) upon hitting someone, cracking and corroding the human's body, leading them to crumble to pieces. Only those with a parasitic Innocence like Allen Walker, Arystar Krory or Suman Dark can heal the virus, sucking the virus out with his teeth (for Allen, his Innocence just cures him of the akuma poison. Krory can also suck the virus out of other humans that were hit by an akuma blood bullet), from these bullets. The Noah Family are also immune to this virus, as Jasdevi drank an entire flask of blood, with the only ill effect is the urge to vomit.

Level 1.5
Level 1.5 is not an actual level per say, it is 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 Walkers 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. 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 2 Akuma come in all shapes and sizes (some have even appeared simply as a gas, fire, a demonic court jester, or even a playing card) 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 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.The only difference between each other is the color of their armor 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. 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.

Giant Akuma
During the fight at Edo, The Earl revealed that a mass number of Level 3's 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 moment 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. After the attack on headquarters, within the dead body of a giant Akuma, emerged a sort of womb which devoured many of the victims of Lulu Bell's attack. From this womb a Level 4 Akuma was born. Prior to this encounter, no Akuma above a level 3 had been seen. The Akuma takes the form a child-like creature with a bloated stomach. There is a black star on the Akuma stomach and a lit, 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 angel. The remnants of the human soul, though not seen, is apparently such a grotesque state that Allen Walker needed to vomit from just a glance of it. A Level 4 akuma has a great amount of speed and power, far superior to the Level 3 Akumas. The Level 4 has been seen to create great balls of energy from its hands and is able to block attacks using it hands and fore arms. The Level 4 which attacked Headquarters was able to fend off attacks from multiple General-level Exorcists before finally being defeated by the combined efforts of Cross Marian, Allen Walker, and Lenalee Lee. Recently, a second Level 4 Akuma has appeared in the manga and attacked Allen, Kanda, and Marie to keep them distracted while the weaker Akuma capture a young boy named Timothy. This Level 4 has the ability to morph it's arms into powerful Gatling-guns which fire the same poisonous bullets that Levels 1 and 2 use. Also like all other levels of Akuma, the level 4 still has to obey the Noah clan, despite being stronger than them, as seen in Chapter 182, though they no longer have to obey the Skulls, unlike the Level 3. The second Level 4 was going to use a beam attack to kill Allen, when suddenly the Noah in Allen came out for a split moment. Consequently, the Level 4 stopped as soon as it realized a Noah was in front of it. Even though the level 4 is stronger, cockier, and crazier than the other Akuma it's still able to be destroyed. When The Earl attacked the Black Order's headquarters, he brought a small army of Level 4 Akuma. The Earl has also hinted that the Level 4 is a stepping stone to something even more terrifying, which is hard to picture.

Mark and Crea
When Crea died in an accident, her husband Mark cursed god for it. The Millennium Earl then came and offered to resurrect Crea, of which Mark accepted. However, Crea, under the Earl's control, was forced to kill Mark and wear his skin against her will. She became a Level 1 Akuma, and was eventually killed by Allen Walker, saving Crea's soul.

Eliade
Eliade is a Level 2 Akuma who valued beauty, but her Akuma nature made her feel ugly. She can produce bubbles that can drain off all water contents of anything that makes contact with these bubbles. When she encountered Baron Arystar Krory III, who made her his woman. Eliade took care of Arystar, in the hopes of not letting him discover that he is an Exorcist. However, this went awry when Allen and Lavi came to their castle, of which Allen's evolved cursed eye revealed to Arystar that Eliade is an Akuma. Arystar was forced to kill Eliade, saving her soul.

Eshii
Eshii is a Level 3 Akuma who is an artist in life, to which makes him yell out "TITLE" before making his action. He has the ability to manipulate gravity with Dark Matter chains. He was sent to kill Lenalee Lee and other Exorcists, all of whom were en route to Edo. After a grueling battle, Lenalee managed to kill Eshii, using his gravity against him, saving his soul.

Chomesuke
Chomesuke is a Level 2 Akuma who has been modified by General Cross Marian. Her human form is a beautiful woman named Sachiko. She was sent by Cross to warn the group of Exorcists, after they defeated Eshii, to turn back due to the impending danger, but at their refusal, she acted as their guide. Despite being modified, Chomesuke could not resist the Earl's command, and due to Cross' programming, she has been designed to self-destruct if her Akuma's blood lust nature surfaces. Eventually, this is what happened, and since she did not die by the hands of an Innocence, it may be presumed that her soul was lost to the Dark Matter. However, if she was manipulated by the Grave of Maria to act so, then technically, she did die by the hands of an Innocence, leaving the question of whether her soul was saved or destroyed.