Robin/Julia

Robin is the main character of the one shot Zone and her appearance, personality, and Innocence are the basis for those of Allen Walker.

Personality
Similar to that of an early-in-canon Allen, but with some large differences in her perspective due to their vastly differing backgrounds.

Appearance
Much like Allen at the start of DGM, but with her hair longer and tied back in a ponytail. The scar on her face has stitches across it, and her left arm also has stitches. She habitually wears a brooch, which has a photo inside it, and generally wears a shirt, trousers, and a long Exorcist coat. There's a round symbol (a seal) on her forehead in the same place where an Allen would have a star, although that is usually covered by her hair. As Robin's seal weakens the sitches streach and it is possible to see what appears to be the "skin" of a Level 0 Akuma through the gap, and as the seal weakens further a small horn grows from this Skin.

Note that she has no canonical hair or eye colour, since there's zero color art of Zone and we don't know if Hoshino ever even picked a color scheme for her. Although she is frequently given white hair like Allen's in much fan art (tending to be brown in the rest), based on a couple of things in Zone canon it is in fact very unlikely that she would have white hair.

Background
Robin is an Akuma wearing the body of a younger brother (the real Robin) who was killed by the Earl in the process of creating the Akuma (the method of creating Akuma is slightly different in Zone). The soul is that of the real Robin's older sister, Julia. 'Robin' is no longer under the Earl's control, presumably having been converted by Cross, and her memories appear to be intact. The thing preventing Robin from reverting to being a normal Akuma is a seal above her left eye. She now works as an assistant Exorcist, with Cross as her teacher, and Cross was the one who gave her the anti-akuma-weapon left arm (it had been Cross', but was transplanted to her). Robin considers it her duty to destroy all Akuma, as she is committed to helping her fellow kind.

Cross was going to take an anti-akuma weapon named 'Abaddon' to Japan to be fixed, but he left without it by accident. And so Robin set off to bring it back to him.

Abilities
Robin's anti-akuma weapon is much like Allen's, although the claw it creates is smaller and more curved, and her gloves stretch to fit it when it activates. It can also activate without changing into a claw. In addition Robin was shown to use the legendary anit-akuma weapon Abaddon when her arm strained her body and seal to the limit. Oddly, doing so restored her seal to full power.

Apart from her abilities as an Exorcist, she's also capable of deliberately loosening the seal on her eye in order to access some Akuma abilities, specifically flying using the wing-like structures that Akuma in Zone are able to have burst out of their bodies, and using her left eye to lock on to targets and manage acceleration.

The stitched scar on her face is in fact part of the seal which is preventing her from reverting to being a normal Akuma. The weaker it is, the longer the stitches holding the sides of her face together become, and it's not a pretty sight when they get long. Activating her anti-akuma weapon is sometimes dangerous for her, because if overused it may sap the power of the seal, making it more likely that she'll revert to the Earl's control. When there is activity nearby from the Earl and/or Akuma, such as when a victim contracts to bring back their loved one, her scar appears to react as if in a warning, and causes her some irritation.