Cayonim is a human-born demon and is affiliated with the Raucos. He appears in the main series, which means Battle of Justice and Hunted. He is the tactician of the bunch, being a specialist in physics and biology which aligns perfectly with the fact he bears Lightning Magic and throws shuriken.

Name: Cayonim
Human Name: Kohaku Ozaki
Nickname: Cayo, Yoni, Yoyo
Race: Demon
Former Race: Human
Birthday: Nov 09
Zodiac Sign: Scorpio
Physical Age: 16
Actual Age: 17
Height: 1.54m or 5'1
Place of Birth: Colchester (State of Atheucia, Uscea) 
Affiliation: Rauco 
Relatives: unnamed parents
Magic: Lightning Magic
Hair Color: blonde
Eye Color: red
Original Eye Color: gray
Mana Level: 91.722 mp
Prominent Characteristics: light blue ponytail, very small 
Phobias: Arachnophobia (Fear of spiders and scorpions)
Status: Alive

Appearance: 

Cayonim is a small young man with blonde hair tied to a ponytail. From the pink hair tie downwards, it's dyed in a very prominent light blue. He usually wears a black high-collar coat and under that a long-sleeved purple shirt and blue jeans or a white t-shirt with a blue neckerchief. However, he also has an alternate outfit consisting of wide, gray pants and a purple combat suit. He has white bandages wrapped around his lower arms and his black inwards bent horns are usually visible. 

Personality: 

Cayonim is a very intelligent person with vast knowledge about science. He's able to figure out how the opponent's magic works by observing and testing it for a sufficient amount of time. He's also very attentive, which causes him to also be able to read attack patterns and adapt to them. However, Cayonim has a very short temper. Calmness isn't his strength at all, it doesn't take much to make him shoot through the roof, like a comment about his size. That also makes him slightly aggressive, wild and impatient. He is very courageous and gritty, shown as he takes battles head-on without hesitation. He's also plain and usually very witty and, more often than not, pretty verbally offensive. Despite that, he's quite a cooperative person, if quite energetic and easy to be set off. He sometimes can be quite demanding as well. He's very careful, confident, diligent and determined and, under normal circumstances, quite disciplined, too. He's an excellent fighter due to his flexibility and methodical approaches and usually takes the initiative as well. He's quite unforgiving, however. He can be mad at someone for weeks straight. He's respectful towards most people (some exceptions made) and doesn't have a lot of self-control and restraint. He usually responds quite violently to the constant teasing of others, but that doesn't quite stop them from perceiving him as adorable. He sometimes isn't allowed to participate in strategy games because he is "too clever", which sometimes causes him to feel left out. 

Past:

Cayonim and his two siblings, Sophia and Suzu, grew up in the little village of Colchester near Solaris. Due to their parents traveling a lot due to being carneval workers, the three of them had a caretaker at their home often. However, the female caretaker named Katherine Charnock started to behave strangely at some point. When the parents where gone for a longer time, she suddenly started assaulting and torturing the kids, beating them, pressing burning hot cigarette stumps onto their skins and pulling out their fingernails. Sophia was the first one who perished in front of their siblings' eyes. Charnock then forced the other two to find all the valuables of the family home and bring them to her, mostly money, but they didn't know where to look, so she left her anger out on them, abusing them even more than before by ripping parts of their skin off and using fire to hurt them. She then murdered Suzu in a gruesome way by first stabbing her eyes out and then skinning her until she died- right in front of Cayonim's eyes, letting him hear her painful screams. As she then wanted to do the same to him, he turned into a demon and killed her, being traumatized by what had transpired. As the parents returned, they were shocked by the scene they found and they immediately took Cayonim into medical and psychological care, but he was super unresponsive and terrified. Eventually, he turned so crazy that he ran away. Eventually, he ended up being found by Lucifer and taken to Rauco where Memory Magic user Inukai deleted all the traumatizing past memories so he could return to functioning normally.

Relationships: 

To Lucifer: He's pretty much the only reason he's staying in Ravarynn. He respects Lucifer, both as a friend and a leader and stands ready every time to help him brainstorm. 

To Inukai: Cayonim allowed her to erase part of his memory, not because he trusted her but because he didn't want to stay broken. He oftentimes asked himself if he wanted to get them back since he was curious about what happened to his family, but he ultimately decided not to plead her to give him his memories back. 

To Azra: Cayonim and Azra do not really get along, mostly because Azra likes to pick on his size, one of the many things to trigger Cayonim's rage with. 

To Tir'an: Since Tir'an tends to be teasy towards Cayonim as well, they oftentimes argue and it can sometimes get physical, with Tir'an ending up paralyzed. 

Magic and Abilities: 

Cayonim's Lightning Magic, also commonly referred to as Electricity Magic or alternatively referred to as Induction Magic, Thunder Magic (even tho that's just plain wrong and missing the point), Charge Magic, Flash Magic, Power Magic, Bolt Magic, Static Magic or Fulmination Magic, allows him to generate and manipulate electricity and lightning, or, more specifically, influence the flow of electrons or charged ions. It also enables him to use all physical capabilities of lightning, such as its tendency to "search" for better conductors when discharged upon the ground, as it has high impedance, which results in Cayonim being able to cause indirect strikes as the current wires through a person's legs instead and discharges within them.

Spells: 

-Heavenly Arrows (The user unleashes lightning bolts shaped like arrows from the sky and makes them hit their target.)

-Electric Shocker (Includes Lightning Punch and Lightning Kick: The user charges any part of their body, mostly fists or feet, up with electricity and deals a huge blow to them via physical contact, unleashing all of the electricity into their bodies, which can cause heavy paralysis and burns.) 
-Charge-Up Beam (The user sends a pretty strong lightning beam from their palm at the foe.)

-Electrical Field (The user generates an electrical field around them whenever they utilize their magic, causing them to accelerate the charged particles. This gives them the advantage of fast attacks and physical acceleration of their own body.) 

-Flash Cannon (The user sends a bright orb of lighting onto their opponent which can blind them.)

-Lightning Discharge Wave (The user creates a wave of lightning around themselves that hits all targets in a certain radius.) 

-Lightning Storm (The user generates multible high-voltage flashes that vigorously rage on the field.)

-Lightning Dispatch (The user sends out multiple little lightning bolts from their hand.)

-Raikiri (The user surrounds their hand with lightning and stabs the opponent with it like with a sword.) 

-Dancing Light (The user gathers electricity and shoots it at the target in the form of orbs- one at a time or all at once.) 

-Zeus' Spear (The user forms a spear of lightning and throws it at the enemy. They can also generate multiple at once and fire them off.) 

Weaknesses: 

-Metal Magic, under circumstances. If the user creates a faraday cage around themselves, the lightning can't reach them. They can also use lightning rods to protect themselves. Otherwise, Metal Magic is weak to Lightning Magic due to being able to conduct. 

-Magnetism Magic, as it interferes with the lightning and can alter its direction. Also, it can disturb the formation of lightning since they can drag away the electrons.

-Earth Magic, to a degree, as the high impedance of rocks and soil limits lightning.

Trivia: 

-Cayonim suffers from severe motion sickness. 

-Despite being Scorpio for a zodiac, he's afraid of scorpions.

-His name is derived from "Caim" (or "Caym"), a great president of hell often pictured as a black bird.

-Cayonim is a gamer of nature.

-His flower is the purple Heather/Erica, for it represents admiration, first and foremost. Cayonim, being the intelligent and sly person he is, is admired by others a lot for his great memory, his ability to apply scientific knowledge anywhere it is required, and his incredible speed, both physically and in mind. However, the Heather also is a sign of solitude. Cayonim isn't able to remember anything, because he asked Bacarra to delete his traumatic memories- but with that, he's also lost his entire family. He has no particular person to confide in, as he's not close to anyone and got no one left from those he's once been loved by, which results in him feeling lonely and excluded.