Ghouls

A kagune (赫子, red child) is a ghoul's predatory organ and functions as their weapon and claws. It is usually as red as blood (the colours are varied in the anime to distinguish the Kagune of each individual), flexible like the flow of water, but firm and sturdy. 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 "liquid muscles". The Rc cells are released from a kakuhou piercing the skin, and the released Rc cells form the Kagune. The Kagune are voluntary muscles as ghouls can control them whenever they want and repeatedly harden and soften them at will. Kagune size depend on the Rc cells quality and quantity while the shape depends on the creativity and intellect of the user.

Although a ghoul's healing ability is high, the healing of wounds tends to be delayed if the wounds are inflicted by a Kagune. It is also evident that in order to counter a kagune in battle, one must also have a Kagune, if not, at least something in relation to a kagune. Hence, Ghoul Investigators use kagune-based quinque as a tactical means to battle against ghouls.

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 characteristically subdue another type, although it may be different for two specific opponents.

Each Rc type has a set of strengths and weaknesses, each one unique to its type. These are exploited by the CCG in the creation of the quinque and Q bullets.

Ukaku
Ukaku Kagune (Japanese 羽赫, romanization ukaku, English feather-red) is spread out like feathers and is released from the shoulder area, it specializes in high speed attacks, most of the users seeming to have highly enhanced speed. The Kagune is lightweight and can be used to deliver high-speed attacks against an adversary, the primary method of attack is crystallizing their Kagune to deliver a high speed torrent of spike-like projectiles, however whilst crystallized they are much stiffer and can't be used for short range combat; at least one Ukaku-type can generate powerful lightning-like bolts, a possible rare ability. While the Kagune is suited both for short-distance and long-distance attacks, short-range is considered their weakness. They are able to use their Kagune as a shield and some users are shown to be able to shape them into sharp blades, reminiscent of a Koukaku, to aid in close quarters, many have shown to be able to increase the flexibility of their Kagune for short-range combat, though this makes it ill-suited for their distinctive long-range attacks.

Altogether Ukaku-type ghouls have a high chance of ending a battle quickly, releasing Rc cells depletes stamina. Thus, Ukaku-type users lack endurance and are at a disadvantage if the battle drags on for a long time. Ukaku-type users can use their speed and mobility to shoot down Bikaku-type users from afar. However, a Koukaku-type user can suppress an Ukaku-type user by successfully guarding against the Ukaku-type user's attacks, leaving them vulnerable to counterattacks and exhausting the Ukaku-type user in the long run.

Koukaku
A Koukaku kagune (Japanese 甲赫, romanization kōkaku, English shell-red) is released below the shoulder blade. Due to its high density of Rc cells it is heavy and extremely robust, giving it the greatest sturdiness and making them very well 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, blades, and swords.

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 scale-red) has an appearance similar to scaled tentacles and is released at the back around the waist. A rinkaku wielder has powerful regenerative abilities and some could even survive the most critical of damage. Its peculiar appearance and structure yield a superior striking power and they excel in brute strength. Some rinkaku users are able to manipulate the shape of their kagune, such as changing its usual tentacle form into swords or claws.

This type's regenerative power is a result of the Rc cells easily binding together. Their Rc cells are similar to liquid. However, this means that the binding force among the Rc cells are weak, therefore making the kagune very soft and easy to break. But because their Rc cells bind so easily, some rinkaku can bind their multiple tentacle-like kagune together to make a larger, stronger kagune. So far the number of tentacles that rinkaku users can create are from one to eight tentacles.

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 fighting against the balanced bikaku kagune: A bikaku has comprehensively high power, allowing them to fight against the brute-force rinkaku, and the rinkaku kagune softness 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. It has been shown that in some cases, a Bikaku attack can disable a Rinkaku regeneration.

Bikaku
A Bikaku kagune (Japanese 尾赫, romanization bikaku, English tail-red) typically has a tail-like appearance and is released around the tail-bone/coccyx. 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." So far, the number of tails that a bikaku user can create are one to four tails.

A bikaku has better speed and durability against the brute-force, breakable 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.

Kakuja
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 transformation kagune also takes after the Rc types.

(A system to become a Kakuja is in the works)

Chimera
When ghouls with different Rc types have children, there is a small chance that they will inherit abilities from both parents. This trait appears to be extremely rare, with only three known examples appearing in the series.

(We aren't allowing any of these in roleplay currently.)

Detachment
Though the method has still not been explained, some ghouls possess a rare ability to detach part of their kagune. This detached piece maintains its traits for some time, and continues to function separate from the main body. Thus far, two distinct uses have been observed: Walls and traps.

A detached kagune wall buries into the ground, and sprouts like a thorn bush or other organic barrier. It extends itself to fill the entire area, making passage impossible.

A detached kagune trap can be buried within any surface, and coils up on itself. These traps will lie in wait until nearby movement triggers them, bursting from their hiding place to impale whatever set them off. It appears to be possible to set more than a half-dozen traps at a time, though the exact limitation is unknown.

(This is up for discussion, message a mod if you are interested!)

Information for this page was found here.