Character: Allen Walker

Allen Walker is a soft-spoken and warm-hearted 15-year-old Exorcist of British origin and the main protagonist of the series. Allen was abandoned by his biological parents because of the paralysis and supposed "deformity" of his left arm and at age seven was adopted by Mana Walker. Three years later, Mana died and Allen turned him into an Akuma, hoping him to be fully resurrected. Instead, he cursed Allen and sliced through his left eye, giving him the ability to detect disguised Akuma. It was at this same moment that Allen's left arm first awoke as an anti-Akuma weapon and instinctively destroyed the Akuma. He was later found by Cross Marian and trained as his disciple until he was sent to the Black Order's Headquarters five years later to officially become an Exorcist.

His Parasitic-type anti-Akuma weapon goes through two different forms resembling giant arms until it reaches its true form, the Crown Clown, which takes the form of a type of fur cape and a giant claw. Later on, it is able to additionally produce a large sword from Allen's left arm, resembling the sword the Earl uses. Shortly after his anti-Akuma weapon takes the form of the Crown Clown, his synchronization rate exceeded the percentage required for General level. When the Crown Clown was created, Allen claimed his right hand was for the human race and his left for the Akuma.



Source: Wikipedia, edited.