Allen also uses his Innocence to fight the Millennium Earl, who created an army of Akuma to destroy the world, and his superhuman followers the Noah Family.

Hoshino designed Allen's clothing to resemble that of the 19th century, giving him a ribbon tie and other accessories to make him appear gentlemanly.

Merchandise featuring Allen's likeness, including plush dolls, figurines, clothing, and cosplay pieces, has been offered.

The manga creator Katsura Hoshino originally had no plans to create Allen's character in D.Gray-man; she wanted the Millennium Earl to be the story's protagonist.

Hoshino created Allen because she found the Earl unsuitable for use as a main character in a manga magazine aimed at teenagers.

[7] She believed her final design looked best wearing a Black Order uniform and wondered if the character should be more masculine.[vol.

1:61] She planned to design the character as an "energetic youth with messy fly-a-way hair", but when he was drawn with the Black Order uniform, the group Allen joins, she sensed a "lack of coordination".

[7] To increase the effect of Allen's arrival at the Black Order, Hoshino gave him the nickname "Destroyer of Time", which has no relevance to the story.

[7] Hoshino demonstrated Allen's dark side by having the character strike his master Cross Marian in anger at his inability to learn how he would become the 14th Noah descendant Nea D. Campbell.

[11] For the arc involving the Third Exorcists, Hoshino's editors advised her to draw Allen as a fighter for the sake of the manga's characters Yu Kanda and Alma Karma, who are heavily featured in the saga.

Because Hoshino wanted the Order and its enemies to have visual contrast, she gave Allen and the Exorcists black cloaks to give a "gloomy" impression.

Allen's clothing is drawn from Hoshino's interpretation of late-19th-century costume; his ribbon tie and other accessories are intended to project a "gentlemanly image".

Because Allen trains to regain his Innocence in a sub-branch of the Black Order, Hoshino wanted to show his real powers.

[6] Because Allen hides his identity from the Order but still claims to be an exorcist in a later arc, Hoshino conceived a new design for him that represents his self-proclamation of being one.

Hoshino's editors were relieved when she told them upon Allen's revelation, he would not be bald and his un-made-up face would be revealed to retain the character's visual appeal.

9:187] During the recording of the anime, Kobayashi befriended the Earl's voice actor Junpei Takiguchi, much to Hoshino's surprise.[vol.

[7][8]Despite his friendly demeanor, Allen is obsessed with the idea of exorcising demons and does not care for his own wellbeing, often clashing with the Black Order.

Despite difficulties in writing him, Hoshino liked the challenge, expecting future manga protagonists would also provide authors with this problem.

Because Jump Square—the manga's host magazine at the time—was aimed at a young male audience, Hoshino said she wanted to characterize Allen as a cheerful person rather than a troubled teenager.

After Allen leaves the Order, Hoshino told readers his life might be arduous and that he would cheat at gambling, a skill he learned while training with Cross Marian.

Allen's deformed left arm awakens, becomes an anti-Akuma weapon later called "Cross" (十字架, Kurosu, クロス lit.

1:61] He is often accompanied by Timcampy, a small flying golem his mentor Exorcist General Cross Marian gave him.[ch.

170] Allen controls his body but he begins turning into Nea; the Sword of Exorcism hurts him, despite it only affecting Noah and Akuma.[ch.

Allen drinks a serum and remembers he was once a normal adult man who was tutored by Bookman Jr. and that he already made a contract with Nea.

[33] Otakuzine regarded Allen Walker as one of the best exorcists in anime history for his caring nature, most notably because he wants to save the Akumas.

[35] Allen's redesign for Hallow received similar reactions from Amrita Aulakh of Pop Wrapped, who stated he is one of the best Shonen Jump protagonists alongside Gintoki Sakata from Gin Tama.

[38][39] Active Anime's Sandra Scholes found Allen mysterious, citing his arrival at the Black Order and the anti-Akuma weapon.

[44] In "Portrait de l’adolescent en Héros à la cicatrice", multiple writers studying clinical psychology said there is a tendency in manga aimed at a young demography to feature heroes with noticeable scars.

Rather than making Allen look like a hero, the protagonist' mark is a cross-like stigmata, a scar-tattoo on the left eye reveals the Akuma he fights across the series.

[45] In the book Representing Multiculturalism in Comics and Graphic Novels, Jacob Birken wrote Allen's use of his powers illustrates the series' theme of identity; although Allen seems to become more human through his Innocence, the revelation he is connected with his enemies generates a major contrast to other exorcists' arcs and other, more-common anime characters.