Fiend

**Fiends** are an ancient race of monstrous, supernatural, immortal beings and the central antagonists of *The Chronicles of Japan*.

## Overview

Fiends are a carnivorous, vampire-like species whose primary diet is humans, consuming their flesh and blood. Sunlight is deadly to them and will burn them to ash, so they strictly operate at night. Fiends have an abnormally powerful physical constitution and potent regenerative abilities, making them immune to normal weaponry and granting them the ability to heal from any wound with ease, even re-growing their head. Only the Nichirin Swords, special weapons made from special ore with sunlight absorption properties, can inflict life-threatening wounds. However, even with a Nichirin Sword, the only method guaranteed to kill a fiend is through decapitation. Fiends are also known to hate wisteria, which are poisonous to them and whose smell is repudiated by them.

Practically all fiends possess a murderous instinct to kill and devour humans, and have lost most of their memories from their human life. While they do still retain their original personality, most times it becomes a darker version of what it used to be, often corrupted by their core beliefs and their past. However, there are a few fiends who have completely retained their human emotions and memories, such as Winter Nakashima, Eden and Lust. Certain members of the Fourteen Kizuki also retain their human memories such as Yua (though she eventually lost her memories later on). All fiends do regain their memories moments before they die, which possibly means that fiends also have their lives flash before their eyes before they turn into complete ash.

### Appearance

Fiends come in a variety of forms. Most are humanoid in appearance, only with slight alterations to their physiology, including but not limited to: paler skin, fangs, pointed nails, cat-like eyes with unusually colored sclera, dark markings that come in various patterns across their bodies, and/or a change in hair color. The changes differ from fiend to fiend, as some fiends can still retain their normal appearance while others gain distorted features like multiple heads, mouths, or limbs. There are also cases where fiends possess bizarrely monstrous physiologies more akin to beasts than humans.

### Behavior

Fiends for the most part work in solitude not bothering to group up and are in fact shown to be highly territorial and fight over both prey and potential hunting grounds, the sole exception is the Spider Family, a group of fiends forced to work together by their leader Yua in what was a hostile environment. Nonetheless, fiends are all for the most part connected to their progenitor, Envy Kibutsuji, who through an array of curses is able to read their minds, witness what they see, discern their location, and even destroy them remotely, operating akin to a hive-mind. All fiends pledge obedience to Envy, who uses fear and manipulation to maintain loyalty. However, Envy's control over her progeny is not omnipotent. An individual with a strong will might be able to sever their connection with Envy, rendering them immune to her curse and making them mostly undetectable by her. The only fiends known to do this are Lust and Winter.

## Abilities

**Accelerated Growth Rate:** Fiends grow at tremendously rapid rates, dependent on the number of humans they have consumed and the amount of Envy Kibutsuji's blood they have assimilated. This allows even the weakest humans, like Yua, once a frail and weak young girl, to become one of the most powerful beings in existence in mere months. As a result, fiends are able to reach further heights that are impossible to attain when human as long as they keep assimilating Envy's blood and consuming humans. Some fiends, however, have a limit to how much they can use to grow stronger, and they might be not compatible with a higher amount of Envy's blood and die if they don't consume enough humans.

**Biological Absorption:** Some fiends have displayed the ability to absorb biological matter into their bodies through physical contact, mainly as an alternative method for consumption. It is also implied that fiends can kill other fiends by absorbing them into their bodies, as Kokushibo absorbed the fiends that lost to him in Blood Battles. Envy also used this ability to nullify a Fiend Blood Art that pierced her body.

**Disease Immunity:** Fiends have an innate immunity to all types of diseases and ailments, with complex anti-fiend drugs and poison derived from wisteria being the only exception, the former being able to effectively weaken fiends and the latter able to kill fiends if they receive even milligrams of the substance.

**Enhanced Senses:** Due to their predatory nature, fiends possess very sharp sensory abilities. Most notably, fiends can discern normal blood from marechi blood. Even a low-level fiend like the Slasher was able to trace the smell of a bento box back to its maker from a great distance. As noted by Envy, fiends are able to distinguish things humans hardly understand, such as blood type, sickness, and genes.

* **Extrasensory Perception:** Some fiends have developed a form of extrasensory perception that enables them to discern the aura of fiends and humans alike.
	+ **Immortality:** Fiends do not age, possessing eternal life that allow them to life for centuries without showing the slightest sign of deterioration or aging. They are unable to be killed by conventional means, like suffering excessive injuries, but can be killed by sunlight, through decapitation by Nichirin Swords, wisteria poison or if Envy wills it.
* **Regeneration:** Fiends have incredible regenerative abilities far superior to any living being or human due to the properties of Envy Kibutsuji's demonic blood, able to heal any sort of physical injury in mere seconds, including deep cuts, organs, chunks of flesh, entire limbs or even their head and entire body. Stronger fiends can heal more serious injuries faster and more precisely than weaker fiends. For example, the average fiend would take a few moments to regrow an entire arm, while the likes of the Upper Ranks can repair it in the same second it was sliced off, faster than even most skilled Demon Slayers can react to, making it seem like it happened instantaneously. The fastest and most impressive regeneration feats belong to the Demon Queen, Envy Kibutsuji, who can heal any injury so swiftly that it makes it seem to marked Hashira that the attack simply phased through him or that he never got injured in the first place.
	+ **Unlimited Stamina & Endurance:** All fiends have a shared physical trait of endless and limitless stamina and vitality, simply being unable to accumulate fatigue or get tired no matter how hard they try to exert themselves. Fiends can also endure pain and discomfort much better than humans and even the likes of Hashira, taking on onslaught of attacks as if they were nothing, such that a severed arm or slashed neck wouldn't even bother them. It is also revealed that demons don't need to sleep.

## Weaknesses

**Sunlight:** The greatest threat to nearly all demons is sunlight, which ignites their cells, severely limits their regeneration, and fatally burns them to ashes. The only demons so far to have developed resistance to sunlight are Winter Nakashima and Fritz Nakashima.

**Nichirin Swords:** Nichirin Swords are blades made out of **Scarlet Crimson Iron Sand** and **Scarlet Crimson Ore**, which absorbed sunlight to such an extent that a decapitation strike with such a weapon can instantly kill a fiend. There are exceptions, however, as Envy, Akaza, and Kokushibo overcame this weakness and survived decapitation by these blades.

**Wisteria:** Wisteria is a plant that is poisonous to fiends, and releases a scent that can repels them. Extract from the plant can be used to create deadly and highly potent poison mixtures to easily kill lesser fiends in small amounts, and later contributed to the death of Upper Rank Two Doma, though he had to ingest over 700 times the lethal dosage.