Okay I can't really explain this well so all the information I post here is from the Tokyo Ghoul wiki. I suck. Sorry.
A Kagune is a ghoul's predatory organ and functions as his/her 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 "liquid muscles". 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.
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.
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.
An Ukaku kagune 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.
A Koukaku kagune 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.
A Rinkaku kagune has an appearance similar to scaled tentacles and is released at the back around the waist. A rinkaku has powerful regenerative abilities and its peculiar appearance and structure yield a superior striking power. A rinkaku excels in brute strength.
A Bikaku kagune 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."
she sends her heart my way and says she's sorry.. I've been struck by Ahri.