Nurarihyon

Personality
Itsuki is a lot more easy going and friendly than the rest of his family, despite what he has been through. When he was a child he would often play pranks on his family members. When he was punished by his parents he seemed to not care in the slightest.

History
As a child, Itsuki always was just like his mother and it was very obvious that Itsuki will become even more like her as he grew up. So when Shayera had a feeling of foreboding a couple of days before Raikardo possessed her, she went immediately to the ten-year old Itsuki. She told Itsuki that she had a feeling that things will change dramatically in a little while and it was up to Itsuki to help guide his brother's down the right path to fixing this change.

Shayera then told Itsuki very specific instructions that he must follow in a couple of days. The first part of her instructions was for Itsuki to not interfere in any family affairs until the time is right and remain as unnoticeable as possible. The second was for Itsuki to freely let his inner primordial demon blood flow through him for a whole night. Shayera continued to say that by doing this, demons throughout Earth Land will begin to stir and follow him as their leader. The last part of Shayera's instructions was to wait for the right moment to strike down his family's problem without mercy. After saying these things, Shayera apologized, by saying his brothers and sisters might resent him, but that he must endure it for the sake of his family. After apologizing, Shayera snuck Itsuki out of the house and threw him into a train that was headed to Fiore.

Demon Hybrid Physiology

 * Remarkable Physical Prowess: Taiga's legendary combat ability.gif Itsuki's body was pushed passed its limit more times then he could count when he was a part of the Chaos Soldier Project. Luckily, though his body seemed to be quite capable of adapting quickly. What came of this was Itsuki obtaining physical abilities that are far superior to most demons. Unlike a certain older brother of his, Itsuki knows how to use it. Shown by his god-like combative abilities. He is able to take on and defeat his entire guild by using mostly his physical abilities.
 * Agelessness: Itsuki's body is in a state of temporal stasis ever since he turned 18. He is unable to grow older, giving him the ability to stay in his prime forever.
 * Enhanced Senses:
 * Augmented Mental Abilities: Itsuki is widely regarded as a very wise and knowledgeable person even though he doesn't act like it all the time. His mind is so powerful that he has obtained a very accurate danger sense that stems from his life experiences, reasoning skills, situational awareness, and encyclopedic knowledge.
 * Demon Lord Form:
 * Ominous Presence:

Quotes

 * "If you kill me, I will become more powerful than you could ever possibly imagine." - Itsuki's last words.

Trivia

 * Itsuki was inspired by the legend of Nurarihyon.