Yuuka is a special case. Like some high-ranking Investigators like Kureo Mado, she possesses and uses multiple Quinque in battle. What makes her special is how she uses them. After a long career of throwing herself recklessly into battle against high-ranking Ghouls with little concern to her own life, Yuuka has lost a lot of things. Her arms, a segment of her jaw and a few of her teeth, the left half of her face, and everything below the waist. To compensate for this, she uses specially-made Quinque as replacement limbs. Appearing as prosthetics when not in use, she carries them literally on her person at all times instead of in a bag or suitcase, allowing her to blend in more naturally in areas where there are Ghouls. They include:
-Right Arm "Migi" (Rinkaku): A tail-like appendage with many leg-like cilia that ends in a poisonous pincer like an insect. The tail's appearance most strongly resembles the spider-tailed horned viper, and it can expand and contract, giving her arm a longer range of movement (at the cost of opposable thumbs while in use).
Pictured here in its inert form.
-Left Arm "Hidari" (Koukaku): A giant, club-like arm that's in gross misproportion to the rest of her body. It can be used to shield her and has a powerful punch, and when cocked back it can be fired like a pile-driver in an attack with a slow windup but a devastating finisher, capable of obliterating cars and mortally wounding most Ghouls.
-Lower Body "Hara" (Bikaku): Her legs have been harvested from a single Ghoul and take the form of raptor-like insectoid legs that have a powerful kick and can run and jump at incredible speeds. Her maximum jumping height is 240 meters and she can run at 370 kilometres per hour, roughly one-third of mach speed and faster than the human eye can follow. This allows her to keep up with the fastest S and SS-rank Ghouls without an Arata, pursue prey across the city and over extreme vertical obstacles, and even dodge bullets to some limited capacity, much like A and S-rank Ghouls.
Pictured here in their inert form.
-Face "Me" (Ukaku): A flesh-like covering that hides the left half of her face that was clawed off by a Ghoul, it is easily mistakable for a burn mark, but when it unfolds it becomes six small, featherlike wings capable of firing crystallized Rc cell bullets at high-velocity. Or in other words, a Quinque gun. Like ukaku Ghouls, it has limited stamina and thus limited ammunition, although its exhaustion affects Yuuka little. Therefore she uses it sparingly as a trump card when backed into a corner.
Due to the way her prosthetics are designed (and due to the way prosthetics work in general), her nerves must directly interact with the Rc cells in her new limbs in order to control them, meaning she is directly interfacing with Ghoul flesh when using her Quinque. The more of her limbs' powers she uses, the more violent and irrational she becomes, attacking friend and foe without thinking and even losing control of her limbs. The longer and/or harder she fights, the more feral and Ghoul-like she becomes. Whether this is her limbs having an effect on her body and mind or just the result of adrenaline mixing with painkillers and antidepressants is unclear.