Kagune

A Kagune (Japanese 赫子, romanization kagune, English approximately shining one ) is a ghoul's predatory organ and functions as his weapon and claws. When released, a ghoul's physique is strengthened, they are more resilient and their mobility heightens. A kagune is composed of Rc cells, which flow just like blood, can become as solid as teeth and can be described as "muscle liquids". The Rc cells are released from a kakuhou piercing the skin, and the released Rc cells form the kagune. A kagune can be repeatedly hardened and softened at will by the ghoul.

Although a ghoul's healing ability is high, the healing of wounds tends to be delayed if the wounds are inflicted by a kagune.

Rc types
The kagune's appearance and the place of emergence on the body depend on the Rc type of the Ghoul.

There are four different Rc types: Ukaku, Koukaku, Rinkaku and Bikaku. As a guideline, each type can characteristcally subdue another type, although it may be different for two specific opponents.

The different Rc types originally developed so that a ghoul of one type can win against a ghoul of a disadvantaged type in turf wars.

It is also possible for a child to inherit separate kagunes from each parent to express distinctive hybrid traits.

Ukaku
An Ukaku kagune (Japanese 羽赫, romanization ukaku, English approximately shining feather) is spread out like feathers and is released from the shoulder area. The kagune is lightweight and can be used to deliver high-speed attacks against an adversary. The kagune is suited both for short-distance and long-distance attacks. Altogether, ukaku-type ghouls have a high chance to end the battle after a short time.

However, releasing the Rc cells extremely decreases stamina. Thus, ukaku-type users lack endurance and are at a disadvantage if the battle drags on for a long time.

Ukaku kagune can use their speed and mobility to shoot down a Bikaku-type user. However, a koukaku-type user can surprise an ukaku-type user by successfully guarding against the ukaku-type user's attacks, leaving the Ukaku vulnerable to counterattacks and exhausting the ukaku-type user in the long run.

Koukaku
A Koukaku kagune (Japanese 甲赫, romanization kōkaku, English approximately shining shell) is metallic and released below the shoulder blade. This is achieved by a high density of Rc cells. It is heavy and extremely robust. Of all the kagunes, they have the greatest sturdiness and are especially suited for defense. Normally, they are generally shaped into armors or shields. But on the offense, they can be shaped like melee weapons such as drills, hammers or blades.

Due to its high weight, a koukaku's speed is inferior to all other kagunes and the kagune is hard to wield.

A koukaku can fend off an ukaku onslaught using its guarding capabilities. However, a rinkaku kagune can deliver severe strikes against the slow koukaku, breaking their kagune and breaching their defenses.

Rinkaku
A Rinkaku kagune (Japanese 鱗赫, romanization rinkaku, English approximately shining scales) has an appearance similar to scaled tentacles and is released at the back around the waist. A rinkaku has powerful regenerative abilities and tis peculiar appearance and structure yield a superior striking power. A rinkaku excels in brute strength.

This type's regenerative power is a result of the Rc cells easily binding together. Their Rc cells are more similar to liquids. However, this means that the binding force among the Rc cells must be weakened, so the kagune are very brittle.

A rinkaku kagune can deliver severe strikes against the slow koukaku, penetrating the kagune and breaching the koukaku's defenses. However, a rinkaku has serious problems to fight against the balanced bikaku kagune: A bikaku has comprehensively high power, allowing them to fight against the brute-force rinkaku, and the rinkaku kagune's brittleness makes it comparatively easy for the bikaku to cut the kagune off. This disarms a rinkaku no matter how much strength it may possess, leaving the rinkaku at a disadvantage on the defensive.

Bikaku
A Bikaku kagune (Japanese 尾赫, romanization bikaku, English approximately shining tail) typically has a tail-like appearance and is released around the tailbone. It is good for medium-distance attacks and has decent offense, defense and speed. Thus, they have no notable strengths or weaknesses like the kagune based on other Rc types, meaning the kagune itself is treated as a surprise "trump card."

A bikaku has better speed and durability against the brute-force, brittle rinkaku, allowing them to cut off the rinkaku's kagune. However, a bikaku will be overwhelmed by the faster ukaku user and will lose against the ukaku's long-range attacks.

The balanced characteristics makes the kagune a preferred quinque type for investigators.

Effects of Cannibalism
When ghouls repeatedly cannibalize other ghouls, they rarely develop an abnormal kagune apart from the common predatory kagune. This kagune typically takes an armor-like shape, and ghouls with such a kagune are called kakujas.

This abnormal kagune also takes after the Rc types.