The Shishio are a clan of Oni's classified as Ghouls with all the base Oni Horuda abilities but instead of having an Oni triger state they have what are called Kagune. As a Shishio, they have a strengthened desire to eat flesh and in some a desire to eat chi as well and those who have that desire can gain stronger Kagune. If a Shishio is born a Ghoul, some have the chance to have the thirst for chi and if they do, it is marked by being an albino . This chi eating ability is rare amongst the Ghouls and occurs usually only once in a few generations if that.
Ghouls share the same physiology for the most part of a normal Onihoruda with only slight differences as mentioned above and in the abilities.
Ghouls are able to run for many hours and not lose breath. Additionally, they can exert themselves at peak capacity for several hours without use of rest before showing any sign of fatigue. They possess an incredibly high durability. This allows them to take numerous blows of internal or external assaults before succumbing to the effects and surviving explosions with barely a scratch on him. Ghouls have the incredible ability to defy weight limitations of other members of their race, but not completely break them. Dense, lengthy, or overweight items are easy to move and simple to use in nearly any manner. They can crush, lift, throw, or catch items of great weight. Ghoul's also possess an overwhelming amount of rage, on many levels allowing them to do incredible and also very irrational feats. With this trait, they are able to empty oneself of all rational restraints in battle and completely immerse oneself in combat becoming a dangerous warrior for both friend and foe. The trait allows the Ghoul to ignore fatal physical damage as if it never affected them and continue fighting with a frightening level of stamina. The rareness of this trait makes-up in one's opponent being super strong as it boosts the Ghoul's adrenaline and stamina to the point they are able to wear out their opponent through sheer tenacity and ferocity alone. In most to all cases, Ghoul are able to go in a berserk form through sheer rage when they are imminent damage.
((Informaton taken from the Onihoruda page found here ))
A Kagune 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); and 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 cells that flow just like blood, can become as solid as teeth and can be described as "liquid muscles". A kagune can be repeatedly hardened and softened at will by the ghoul. If one can eat chi, the Kagune can morph into other Kagune forms depending on the strength of the ghoul. To switch between Kagune takes up a lot of chi and one can only switch maybe once or twice per fight.
The kagune's appearance and the place of emergence on the body depend on the type of the Ghoul. There are four different 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 types originally developed so that a ghoul of one type can win against a ghoul of a disadvantaged type in turf wars.
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 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.
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.
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 its 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 cells easily binding together. Their cells are more similar to liquids. However, this means that the binding force among the cells must be weak, therefore making the kagune 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.
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.
Due to the concentration of Chi and other physical properties that the Onihoruda can posess, Ghoul's skin is tougher than a normal human's skin is. Its denser and more akin to metal than actual skin. It can block most if not all styles of bullets, non-explosive projectile weapons, normal blades of most strengths and sharpnesses and peircing attacks of most any kind. Because of this if a normal human tries to punch a Ghoul as well, their bones are most likely to shatter as well due to the hardness of their skin. A weapon of a strong enough material can do damage to a Ghoul but normal human's probably won't have access to the metals needed. Also, if enough force is applied behind a physical attack, you can also damage them.
Ghouls become stronger, faster, more durable, etc. when they come in contact with or are near blood, possibly unlocking abilities related to the affinity and enhancing the existing powers. Some Ghouls may be able draw sustenance from the blood or even slow or stop aging. This ability is cited to be linked with the Ghoul's desire to eat flesh.