Ao no Exorcist OC Wiki


35pages on
this wiki
Add New Page
Comments3 Share
I need this k by chemicalyinbalanced-d8xv86r





Female Female






127 lbs.


October 29th 1994

Hair Color


Eye Color


Professional Status

True Cross Order



Exorcist Information


Personal Status



Silvia (Mother)
William (Father)
Hayden (Hayden) ✝
Eliza (Sister)
Vladimir (Uncle)
Fuyu no Usagi

Japanese Voice

Tamura Mutsumi

English Voice

Tara Strong

Leviathan is an oc that belongs to an AU for Blue Exorcist. In this Au none of the main cast exists except for Satan himself.

Here are some of the head canons for this AU and this character..

I need this k by chemicalyinbalanced-d8xv86r

Brief History

Leviathan was born in Nerima, Tokyo, Japan. She the youngest daughter of Demon- Exorcists William and Silvia. Her child hood was rather generic and human like. Other then she had irregular growth spurts and stayed in her demon form for the first 3 years of her life.  She became friends with a girl during her time in Kindergarten. Her name was Yamauchi Haru {山内 陽} who would later become her girlfriend later on in her life. With Leviathan’s parents being extremely busy, she would be sent to Haru’s house and the two would hang out and do little kid stuff. However, Haru’s parents died in a car accident and she was sent to live with her Aunt and Uncle in Akita. Leaving little Leviathan alone without a friend. She eventually made a few during her time in school. While in Elementary, Middle, and the first two years of high school. Her parents had to fill out a lot of paperwork not only for the schools she went to but the Order as well.

But her tale officially begins when she first arrives at the True Cross Academy.

The young wolf demon was in her second year of high school in Nerima before she was transferred to the True Cross Academy. At the time she was confused on why she was transferred in the beginning of the school year. Until she got a note, explaining everything. Earlier in the year she had filled in application for the school. One to voluntarily become an exorcist despite being a demon. The only reason why she was allowed to set foot on the campus was because of her parents. Both William and Silvia worked alongside the humans for around 841 years. When she arrived at the huge, prestigious school, she wandered around until she finally reached the Cram School after meeting up with an odd looking male dressed in a black uniform, whose hair was grey like ash. That man opened the door for the young 16 year old demon.  As she walked down the old fashioned corridor, she eventually made her way to an older dusty classroom, filled with desk, chairs, and large shelves filled with books. The other students in the classroom stared at her. Because her ears and two fluffy twin tails were visible, Leviathan also wore a different uniform. One student asked her if she was a half demon. All the wolf girl said was,“ いいえ. 私は狼悪魔です.“she glared at the student with her golden orbs before pulling the chair out from under the desk and sitting down. When she said that the teacher had just walked in and pulled out her rapier, pointing it at the young demon, the knight spat questions at the Akuma as she ordered her classmates to leave the classroom.  Before the teacher could lunge a taller figure with silver hair had intervened . That figure was her mother, Silvia, who had entered just in the nick of time. Gently pushing the rapier’s tip down, as she glanced into the knight’s brown eyes.  Leviathan was scared shitless and she just stood there with her tails between her legs, her ears flattened against her head, and her teeth bared. Silvia apologized to the exorcist and pulled a letter from her coat and handed it to her. Confused, the knight opened the letter and began reading. After reading the letter, Silvia explained why Leviathan was there.  The young wolf demon watched the scene unfold in front of her and she finally calmed down. Her mother pulled her aside as the students entered the classroom.  After having a little talk with her youngest.  Leviathan was sent back into the classroom. 

As the year went on, Leviathan found herself partaking in difficult training. Being pushed and pushed to her very limits so that she could prove that she was worthy of being an exorcist and aiding the Order. Leviathan was sloppy with her flames and she couldn’t exactly control her shadows. So when her parents had some free time, they would take turns training their youngest daughter. Little by little she eventually got better at controlling her abilities, but that did little to stop her from getting her ass kicked back and forth.

One night after training with her mother, the tired pup decided to take a walk around in the forests surrounding the school. Her curiosity got the best of her as she wandered about, she ended up walking into another demon’s territory. The large bug demon popped out of nowhere and attacked her. Leaving a nice long scar on the left side of her face, where she later on lost the sight in that eye. The young wolf demon ended up burning the bug to ash before flying with her hand covering her left eye. She returned to her dorm room and attempted to fix the wound herself. Which didn’t work out too well. When her parents found out. Her mother was extremely pissed and scolded her for acting like an idiot. William was upset, but somewhat proud that she killed a demon. They took her to a doctor to get her eye checked out. Leviathan found it extremely difficult, only being able to see with one eye.  It was something she would have to get used to over time.

Leviathan’s time at the Cram School was less than perfect, her fellow classmates didn’t trust her nor did they want a demon as a classmate. At the time everyone was on edge because there was a massacre in Okinawa and Italy. So a lot of them were suspicious of her. Many of them avoided her. Which didn’t help when she had to be paired up. Instead of trying to coexist with them, she grew distant and quiet. By the time the exam rolled by she had already formed a facade, one to protect herself if necessary.  She spent most of her time training and studying instead of socializing with her peers. When that day came, she was separated from her classmates and placed in a different room. After few hours of writing and answering questions on the exam, she handed it in. The demon managed to sneak by with an 83. Even though she passed, she was sent through 5 more years of more intense training before she was allowed to become an exorcist. Leviathan swore an oath. One that bound her loyalty to the True Cross Order. 

Her first mission as an exorcist was pretty interesting. She had to hunt down a demon that took over an abandoned church. The demon’s code name was Hunter. Notorious for their long blade like nails and stealthy abilities Instead of hunting one, she had eliminate a whole nest of them. Being overwhelmed by the small nest, she was forced to transform into her demon form. Which she then proceeded to either chomp down on the nasty little buggers or burn them.. She didn’t go completely unscratched. Leviathan had multiple cuts and gashes all over her body and somehow she managed to burn her side. She wasn’t exactly the happiest camper afterwards. 

As life continued on she had a few obstacles in her way, may it be other exorcist trying to kill her or  her older sister. Whom she never knew about. She was furious at her parents for not telling her that she actually had siblings. Silvia’s reply was that she disowned Elizabeth after killing Hayden her older brother during 1945 when he was attempting to recover dead bodies and injured soldiers from the battlefield. After having a large disagreement with her mother. Silvia simply said it was best that she didn’t know. Which Leviathan never found the reason why. Until she met her older sister for the first time. That didn’t end to well, as the two fought each other. Being the older, more experienced sibling. Elizabeth easily beat her little sister. Leviathan found that her sister isn’t good. She was just there to cause trouble. The younger demon had no choice but to flee. Even if she didn’t want to. 

But life continues on. One day while hanging around the school’s grounds, she noticed someone familiar in the distance. As she approached the person, she noticed the ginger hair and dark brown eyes. When that person turned around, she just gawked at Leviathan before she tackled the 22 year old demon to the ground. That person was Haru, the dear friend that she hadn’t seen since she was 5. As typical, Leviathan’s tails were wagging with excitement. The two talked for a long time before they had to separate once more. Leviathan and Haru began to hang out again, the two talking about life generally, games, fashion trends. You name it. As the two spent more time together, both Haru and Leviathan realized they had feelings for each other. And it was until Leviathan blurted out that she indeed had these feelings. Haru looked at her fluffy friend. Leviathan’s face was completely red and she covered her mouth with her hand. The two sat there for a moment before Haru leaned over and whispered something in the crossbreed’s ear, causing her to freeze and fall down. Thus began their adventure as girlfriends. Then lovers.

As they got older, around the age of 24, they decided to adopt a child. Which meant alot of paper work and waiting.  They adopted a little five year old named; Ryo { 亮 }.  The child had been brought back twice because of her strange behavior and how she saw things. When she met Leviathan and Haru, she was scared. Afraid that she would be brought back to the orphanage.  They then later found out that Ryo had schizophrenia, her being symptoms were delusions, hallucinations, disordered thinking, and etc. As they spent more time with the child, they grew attached to her. Even though she could be quite the hassle sometimes, Leviathan adored her. Ryo eventually managed to warm up to her two new mothers, to the point where she felt safe with them. She often called Haru; Haha. And Leviathan; Rebi. The two eventually figured out that she had quite the vivid imagination. As long as Ryo took her medication, she could function decently in society. 

Leviathan was happy with her little family with Haru. But when her parents found out about Ryo. William drowned from excitement as he attempted to hug the poor kid He could finally call himself a grandpa. Silvia just stared at her adopted grand daughter, then at Leviathan and Haru. All she did was pat the kids head, while William decided to show her around their home surrounded by cats. Amused, Leviathan followed her father leaving Haru to deal with her mother. The two had quite the long conversation.

But all good things eventually come to an end. Leviathan was assigned a mission on December 24th of 2021. Before she left, Ryo insisted that she returned for Christmas. Which Leviathan promised she would. That never exactly happened. She was sent to investigate reported sightings in a power-plant. While looking around a higher leveled demon known as an Intention crept up on her and attacked. While fighting this demon, she managed to shoot it a few times before loosing her right arm and having one of her legs chomped on. The silver bullets weakened the demon, but it continued on. To the point where it ripped some of her innards out and consumed her heart. It then fled from the scene only to be fully eliminated a few days later. She never got to fulfill that promise.


Leviathan is quite odd for a demon, she has a great affinity towards humans. And feels obligated to protect them even if they dislike her. She is very expressive when she talks, either by using her hands to explain things. This crossbreed is still considered a puppy and will in some ways act like one. Either by chasing her tail, whining, chewing on things, and chasing Frisbees. If something defies her logic, she will try to defend it even if it doesn’t make sense. She also likes speaking her mind, unless there is a higher rank in the vicinity. Leviathan is very loyal and would not defy the Order unless she had no other choice. Or her girlfriend. She absolutely adores Haru and will stay with her until the very end. Sometimes she gets really thick headed and stubborn, so have fun changing her mind. Leviathan is very active so its often rare for her to be quiet. She can be calm from time to time. But that is only if she didn’t drink coffee. Coffee and Levi don’t mix too well. 

When she first meets someone, she will be extremely polite. Especially if it is another exorcist she is dealing with. The only time she gets nervous is when she doesn’t have a grasp in a situation or if she is uncomfortable. Or if you point your weapon at her. It has been noted that she is terrified of her fellow comrade, as they either tried to harm her or kill her.  Even if they don’t like her for being a demon and such, she treats her peers with respect. Even if that means her giving her life to save them.  She has gotten used to this suspicion and hatred over time. And knows full well that you can’t force someone to change. 





-An ability she inherited from her mother; Silvia. This pup can control, regular fire, like the fire in your fireplace. Though she is decent at controlling them, she does have limitations. Leviathan can light up a whole normal sized classroom with ease. She can light herself on fire, breathe fire, and toss projectiles around.  -Once in a blue moon, she will burn herself or scorch her tongue. You can easily put her flames out with powder, a fire extinguisher, dumping water on her, hitting her on her head. Though she doesn’t exist in the main verse for Blue Exorcist. Both blue and black flames will over power hers with ease. Shadows -An ability she inherited from her father; William. Controlling the darkness around you is relatively hard and requires a lot of concentration to control. It also requires a lot of training in order to handle them. Leviathan can create a small barrier that will block minor physical attacks, water, and fire. She can morph them into a pair of large hands and multiple tentacles. Also, she can melt into nothing, but that is generally used as a last resort if she were to be stuck in a sticky situation. 

-  After awhile the user will start discharging blood from their eyes, mouths, ears, and nose. The longer they use the darkness around them, the more blood spills out. After awhile the user will become dizzy and pass out. Some cases have been proven that there is possible brain damage.  Silver bullets can pass through the shadows with ease and holy water will cause it to dissipate. Some users are limited to only using this ability at night. Leviathan herself cannot use her shadows during the day unless it is foggy or the sun is covered. 

Minor Healing 

-Her healing ability is shit. She can only heal small cuts to medium sized gashes. Depending on how deep her wounds her. If she were to transform into her demon form, her wounds ill expand.  Same goes for her transforming back. Which hurts a lot so she tends to stay in one form when injured. The only useful thing about this ability is that she can reattach her arms, legs, toes, and fingers. If she continuously attaches them, they become useless and she won’t be able to reattach them after awhile.

Demon Form

-First off Leviathan transforms into her demon form/original form physically. It hurts like like. Likely because she is much larger in this form. That means her bones shift and crack and her body expands. It can take around 3 to 16 minutes for her to fully transform. So she just stays in her human form instead. She also hits harder in this form, but she is slower. And she is really fat. She a fluffy thing. Alright.

———————————— Weaknesses ————————————

-Holy water and holy artifacts. Anything Holy. Okay.

-Wolf’s Bane will cause her nose to block up. She is allergic to wolf’s bane.

- Leviathan is not very strong to began with, so it is easy to punt her around.

-Her heart. Which is any demon’s major weakness. Because she is physically bond in Assiah, she cannot reveal her heart and use her abilities to their full potential. –Her ears and her tails

-Certain high and low pitched frequency will cause her berserk and she will try to find the source of the sound and destroy it.

- Demons with the element of light and water.


Leviathan is unable to have children. So she and Haru adopted a little girl named Ryo. - This pup had a extremely hard time learning English.

-Leviathan really sensitive about her height. She claims she is 5'2 but she is really 4'8.

-People have mistaken her before for a half-demon. This really pisses her off and she will flat out tell you that she’s a full demon not a half-breed. Though she should shut up because she is nothing more than a crossbreed.

-She prefers using her Remington over her other abilities.

-Her handler is Takahashi Aki {高橋 明 } She makes sure that Leviathan gets the information she needs for missions. Shes like a baby sitter.

-She likes dog treats. I mean she reallly loves dog treats.

-Leviathan wears gloves when she reloads her Remington, since silver will burn her hands.  

-She doesn’t drink alcohol.

-She doesn’t like it when random people touch her tail, touch them the wrong way and you know what happens. Use your imagination.

-Leviathan doesn’t like spicy foods, since spice irritates her tongue.

Levi's ref

Leviathan's updated Ref.


Leviathan's old appearance.


Deviant Art- ChemicalyInbalanced

Rp blog- awolf-among-sheep

Ad blocker interference detected!

Wikia is a free-to-use site that makes money from advertising. We have a modified experience for viewers using ad blockers

Wikia is not accessible if you’ve made further modifications. Remove the custom ad blocker rule(s) and the page will load as expected.