CROW

Crow is an elite group of humans from the Black Order who act as special enforcers. Though they are not endowed with Innocence, they possess unique skills and the ability to cast powerful spells to bind their enemies. Howard Link, a former member of Crow, demonstrated this ability against several Akuma while trying to protect Timothy and the other orphans. It was originally believed that Crow was only capable of temporarily hindering Akuma, but their power apparently goes beyond that. A Crow member by the name of Madarao was able to walk through the barrier the Skulls had erected which was powerful enough to block both the Ark and Walker's Eye. Further more, he defeated a Level 3 Akuma with a spell which absorbed it into his hand. This feat apparently came as a surprise to even Link, indicating that he himself is not aware of the full potential of Crow.

Their true purpose and the source of their powers was revealed to be that they were biologically converted, making them into half-human/half-akuma. As a side effect, their bodies do not react well when they come into contact with Innocence. They are able to destroy other Akuma by cannibalism, one of the only two ways to destroy an Akuma. Allen's eye reacts to the Crow members, but doesn't see a bound soul, just a dark aura instead - but only when the abilities are activated. When the Akuma abilities are innactive, they are undetectable to Allen's Pentacle Eye. However, when activated, they tend to respond aggressively to Innocence and their wielders, such as Allen's. Link was shocked to hear they are half-akuma, as he was once a part of the unit.

Powers and abilities
As of the moment, the full potential of Crow has yet to be seen. What is known is listed below. Note that all the abilities listed here are the powers known of the current members of Crow, the Third Exorcists. The extend of the powers of the former Crow members is unknown but implied to be far inferior, as Howard Link was shocked by the power shown by current Crow member, Mararao.

Spell Casters: Members of Crow have show great appitude in using spells and incanations, to the extend of being able to create barriers to hold level three Akuma at bay.

Immense Strenght: Madarao has show an inhuman strenght in that he was able to block a blow from a level three Akuma with his bare hand, with no sign of difficultly, as well as Koushi hurling Allen Walker into a nearby pillar, causing a massive indent in it.

Akuma Presense: Due to the Akuma cells present in their bodies, Third Exorcists count as Akuma as well, allowing them to pass through barriers only Akuma can pentrate.

Akuma Devouring Ability - Devouring Machine, Creation Hole: A truly frightening ability, A Crow member's arm disfigures and opens up, showing a glowing core of energy in the middle of the arm. The arm itself is still connect via several strands of flesh and muscle while a massive hole opens up in the centre of the palm. This ability can effortlessly devour a level 3 Akuma with no trouble, the Akuma being absorbed into the Third Exorcist. What happens to the souls of the Akuma is unknown.

Members
It seems that Renee Epsteine of the North America branch, is in charge of Crow or Third Exorcists, stationed at the Black Order by order of the Pope. Crow consists of five individuals; Tokusa, Kiredori, Koushi, Tevak and Madarao, who were created similar to the incident happening nine years before. This was called the Order's dark legacy by Bak, an incident that may have also involved Kanda.

Former Members
Howard Link An inspector for the Black Order and a former member of CROW, Link was shocked to learn of the true natures of his former squad, leading to a possible theory that the purpose of Crow is far different today then when he was a member.

Triva

 * Considering Howard Link is shocked to discover that his old unit CROW is comprised of half-akuma exorcists, it is most likely CROW's original purpose was quite different to it's current one. What it was remains to be seen.
 * The way in which Third Exorcists are created, being originally humans who turn into human/akuma hybrids through the implanting of akuma cells into their bodies which is the source of their unique powers, is quite similar to how the characters in the Manga series Claymore are created, where they are originally humans who have the flesh of monsters, Yoki, implanted into their bodies to give them supernatural abilities.