Nurarihyon

Itsuki is a legendary demon who is said to have united a hundred demons in a single night. After that night, most demons started to think of Itsuki as the "King of Demons" or the "Leader of all Demons."

Human Form
Itsuki is male who looks like he is around eighteen years old. He has red eyes, short length black hair, and a well-toned body. Itsuki’s clothing is simple, comfortable, and easy to move in. Itsuki wears a tan under tunic under a tan Karate gi top. Occasionally he wears a long flowing black cloak that reaches his ankles. For pants he wears loose-fitting long tan pants. For shoes he usually wears black boots.

Demon Form
When Itsuki enters his demon form he is depicted as a tall man with a gourd shaped head and glowing red eyes. The color of Itsuki's hair is shown to be a combination of white and black, the top being white while the bottom half being black.

Personality
As a child, Itsuki used to have a very prankster-like persona.

The current Itsuki has been described many ways. Tsuki describes him as a kind, merciful, and patient leader and friend, while his opponents say he is a demon one should avoid angering at all costs.

History
Not much is known about Itsuki before that fateful night when he untied a hundred demons. Some believe he was an average traveling demon while others believe he was part of an unknown organization.

Equipment

 * Demon Lord's Sword
 * Magical Clothing: Itsuki's clothing is enhanced by Ethernano, meaning it is a lot more durable than normal clothing. It is capable of fully protecting Itsuki against weak physical and magical attacks. This clothing also emits a sort of aura which protects Itsuki against the elements, such has extreme cold and extreme heat.

Teleportation Magic
Teleportation Magic is a type of caster magic that allows Itsuki to get from one place to another instantaneously. While Itsuki occasionally uses it to cover long distances quickly, its primary use is to give Itsuki an upper hand during hand-to-hand fights.
 * Rift Action - Rift Action is a technique that allows Itsuki to teleport to a spot that he has marked with a magical seal.
 * Direct Line - This is a basic teleportation spell that allows Itsuki to teleport to any location in a direct line.

Light Magic
Itsuki's Light Magic was born from Itsuki's positive emotions and human form. As such, his Light Magic spells are stronger when he is in his human form. The power of his spells doesn't come from how much magical power he uses, but instead how much joy, happiness, love, and other positive feelings he is feeling at the moment or is capable of flowing into his spells. The number of spells he can use depends on how much magical power he has. Like most Light Magic, he can create and manipulate light for offensive and defensive purposes. However, unlike other Light Magic he isn't limited to this. He can also perform feats that align themselves with the good such as calming the anger of a beast, form a friendship with said beast, control his own emotions, enhance an allies confidence, enhance an allies physical and magical abilities, and gain insight into how to create a "righteous" future. The last feat gives Itsuki a "danger sense" when he is in his human form since these emotions are stronger when he is in his human form.
 * Rain of Light
 * Giant Wrath
 * Light Wave: Light Wave is the counterpart of Dark Wave, it is performed in the same way as Dark Wave, but instead of releasing darkness, the user releases light energy.

Darkness Magic
Darkness Magic is the opposite of Light Magic. Itsuki's Darkness Magic was born from his negative emotions and demon form. As such, the power of his Darkness Magic is stronger when he is in his demon form. The power of his spells is based purely on how strong his negative emotions are at the moment and not how powerful his magical power is. The only role his magical power plays in Darkness Magic is how many spells he can use. Itsuki's Darkness Magic feeds on his negative emotions such as fear, anger, greed, hatred, aggression, et cetera. Like most Dark Magic uses, Itsuki is able to manipulate the darkness and other similar sources, but it isn't limited to that. When he is in his demon form, as Itsuki lets his negative emotions consume him he grows stronger and stronger while at the same time creating a darkness in his psyche, which causes him to want to use it again. Itsuki is also able to control the emotions themselves and use them for physical as well as mental attacks. In general, Itsuki is able to create and manipulate anything associated with evil, besides death. These effects can be reversed whenever he feels a powerful positive emotion in him. This is one of reasons why Itsuki likes Tsuki more than any other demon, she is like a barrier that helps prevent him from being fully consumed.

Itsuki is able to use his Darkness Magic to instill feelings of anger, hatred, and similar emotions through his words. The power of this is shown to be enough to cause the Haruhi, a person known for her peaceful nature, to have desires of destruction, but only for a while. Itsuki most commonly uses this ability to shatter alliances.
 * Demon's Intent: Itsuki takes a deep breath and lets out a loud yell, which is infused with his negative emotions. This causes anyone who hear's it be overwhelmed with fear, in rare cases a mage could be so afraid that they are paralyzed with fear. If enough negative emotions are used, it can cause any who hear it to see a vision of their death in their head. Many mages have said that the vision is so real that they actually thought they were dead.
 * Dark Delete
 * Dark Wave
 * Shade Troopers
 * Shade Troopers: Jellyfish Form
 * Dark Grab
 * Dark Moment
 * Demon Blast
 * Dark Deflect
 * Demon Lord Blast
 * Demon Knight: Demon Knight is the advanced form of Shade Troopers. This spell allows the user to create demonic knight-like entities out of Itsuki's negative emotions. Itsuki is able to command these creatures at will from close by or afar. These knights are on the level of super soldiers, but unlike Shade Troopers, these knights can suffer from fatigue or exhaustion.
 * Demon Mage: Demon Mage is the counterpart of Demon Knight. While Demon Knight focuses on sword and hand-to-hand combat, these entities are abe to perform any of Itsuki's spells besides Itsuki's Light and Twilight Magic spells. They are able to perform 20 spells each, regardless of how powerful the individual spell is.
 * Demon Assassin
 * Demon Spy
 * Demon Guard

Fear
Fear is a Caster Magic, usable only in his demon form.

Twlight Magic
Twilight Magic is by far, his strongest form of magic. It combines his negative and positive emotions to create a new form of energy. However, using this magic easier said than done, since Itsuki's negative and positive emotions are separated by his two forms. When he is able to use this magic it is shown to have unbelievable power.

Illusion Magic
The power of Illusion Magic revolves around creating and manipulating illusions to use for combat and supplementary purposes. These illusions are known to be very powerful and can deceive even a very powerful mage.

Summoning Magic
Summoning Magic is Caster-type magic that allows Itsuki to summon objects and beings to his side with the use of magical power. Usually, one has to item to perform this magic, but as a Demon Lord, Itsuki is able to summon demons to his side with performing a ritual or using an item. All that is needed it a sufficient amount of magical power and slamming his hands-on the ground.
 * Summoning: Yuki-Musume

Demon Form
Itsuki's demon form was born by his negative emotions. This means that he can only enter his demon form when he is consumed by a negative emotion.

Immense Physical Prowess
Itsuki's physical prowess surpasses normal human limitations. His strength and speed are incredible which is shown when he uses his unique fighting style.
 * Cold Resistance: Unlike his other physical abilities, Itsuki wasn't born with the ability to resist the cold, but rather, his body adapted after being around Tsuki a lot.

Expert hand-to-hand combatant
During Itsuki's travels, he created and mastered his own unique fighting style. This fighting style incorporates his incredible physical prowess to overwhelm the opponent with both speed and strength. There are many techniques derived from this fighting style including creating afterimages and even using pure Ethernano to perform a powerful punch. The name of this fighting style is: Twilight Fist.
 * Afterimage Technique: The Afterimage Technique that allows Itsuki to move with great speed to not only dodge an attack but leave an afterimage in his wake.
 * EPBG.gif Ethernano Punch: Ethernano Punch is one of the most famous techniques derived from Itsuki's fighting style. Itsuki strikes his opponent with a powerful karate punch. Upon impact he releases a short but powerful blast of energy, this results in the opponent being propelled back with great force.
 * Sixty-four Swift Kicks: Itsuki unleashes a flurry of 64 kicks in five seconds. Each kick has enough power to easily crack a boulder and the speed of each kick is rumored to be 25 mph.
 * Elbow Strike: A seemingly simple counterattack that in involves the elbow. Itsuki waits until his foe is in mid punch, and then he steps inside the opponents guard and delivers a powerful elbow strike to the foe's chest. The strike is strong enough to fracture the enemies ribs. Itsuki then release a powerful pulse of pure Ethernano that can knock the wind out of the opponent and make the foe loose their balance and fall down.

Enhanced Senses
Itsuki's senses are a lot sharper then normal humans. He has incredible vision in the dark, however it takes him awhile to adjust to light.

Superior Intellect and Wisdom
It is estimated that Itsuki has an IQ around 190 and he is wise beyond his years.

Danger Detection
Due to Itsuki's unique Light Magic, while in his human form, he has a sixith sense known as "danger sense". This sense allows him sense upcoming threats and danger, giving Itsuki the ability prepare appropriately. This ability does not allow him to know what is going to happen, just that something will happen along with the exact time that this threat will arrive. While alone with Tsuki, she once said to Itsuki as a joke that this ability is more like "Enhanced Paranoia".

Immense Magical Power
Itsuki is known for having an incredible amount of magical power. His magical power is superior to even Haruhi's magical power.
 * Monster Aura
 * Great Dragon Spiral: Great Dragon Spiral is a technique that allows Itsuki to shape pure eternano nto a strand which wraps around any his right arm or any other body part. This spell can be used for offense and defense.
 * Twilight Sword Slash
 * Magic Annihilation: Magic Annihilation is a magic spell that uses a users on magical power to attack.

Quotes

 * "I guess "Itsuki" isn't a very fitting name for a demon lord, huh? How does the name "Nurarihyon" sound?" - Itsuki talking to Tsuki during the begining of that fateful night.
 * "People who see things in absolutes will never see the true ideals of the Essence of Magic." - Itsuki to a Dark Mage.
 * "My human and demon form both agree, you need to die today." - Itsuki before using Twilight Magic for the first time.

Trivia

 * Itsuki shares his name with a character I created on Naruto Fanon.
 * Itsuki's fighting style is very similar to a fighting style I created on Naruto Fanon called Kaneko Fist.
 * Itsuki was inspired by the legend of Nurarihyon.
 * Itsuki's favorite drink is tea.