Like many Abyssals, she has pale skin, and glowing eyes. There is a mole under her left eye. Her hair is short (or bound-up), black (with a white streak), and styled in the very uncommon side-drill. Additionally, there is an anchor hair ornament on the end of a single sidelock.
Her clothing is all blacks and greys. She is dressed in a meiji schoolgirl uniform that consists of a grey kimono, black hakama skirt & obi, and black high-heeled boots. She also appears to wear black elbow gloves.
She is armed with a monstrous Abyssal gun turret, replete with one-and-a-half horrific, toothy maws, bristling with gun barrels, disturbingly organic-looking mechanical parts, and a hose dangling from the bottom.
While it is very easy to mistake her for Ancient Destroyer Princess, there are some key differences:
- Oni looks far more intact and composed, while Princess looks significantly more damaged.
- Oni's Abyssal turret gun is one mouth grafted to another top set of teeth and a broken, incomplete jaw, while Princess's turret looks more completed: it has merged and integrated the two upper sets of teeth into one, centralized the lower jaw, and fixed up the machinery parts inside.
- Oni's hair is either shorter or pinned up, while Princess's is much longer and/or hanging down freely.
- Oni's side-drill is shorter.
- Oni lacks the white tasuki that Princess wears.