Author's Note: Hello everyone! This is an Ao No Exorcist AU that I decided to write, as I like the whole "evil Rin" idea that some people write, even thought Rin isn't really evil per say in this story, as you'll come to find out. This fic takes place in an AU after Satan's rule in Gehenna is overthrown, and Rin steps up to take his father's place. If you enjoy the first chapter, please leave a fav and a follow and tell me what you liked about it. Enjoy!

Chapter 1: King Rin

Shiemi's bloodshot eyes fluttered open at the sound of a trumpet being blown, signaling her and the other nurses to treat a new batch of wounded exorcists. Pulling on her jacket, she stepped out of her tent and into the frigid winter, the chilly air stinging her nose and cheeks. She witnessed around twenty or so exorcists being hauled in on stretchers, some missing limbs and others bleeding profusely.

"Come on Shiemi, we've got wounded to take care of." her friend Paku said, emerging from her tent and placing a hand on her shoulder.

"R-Right." Shiemi mumbled, following Paku as they both headed to the medical tent. Entering the tent and both of them getting to work on a man that lost an arm, Shiemi recalled how this awful conflict had begun, her eyes watering up yet again.

Flashback:

Rin stood over Satan's corpse, surrounded by his friends who had helped him defeat his blood father. Only hours ago, the Vatican had launched a full scale attack against Gehenna, and Rin and his friends along with their teacher Shura had been a part of the task force entrusted with the job of breaching the throne room and ending Satan's reign for good.

Rin eyed Satan's body with a sad look in his eyes, but they seemed content with what he had done. Picking up Satan's sword, he turned it around and held it in his own hands as he remembered his father's final words:

"Even now, as you stand in my throne room, impaling me on your own blade imbued with my power, I can feel the doubt in your heart. I know that my kingdom dies along with me, but I implore you, Rin, when this is all over, take my sword. It has the ability to see into the hearts of men and demons alike, and before you return to your everyday life, look into the hearts of your 'friends.' You might be surprised at what you find."

Honouring his father's final wish, he drew the black sword, and it was as if his third eye was opened in that moment. The tired faces of his friends showed new expressions, but it was hard for Rin to put into words. He could see what his friends really thought of him, and even what they had planned for him in the future.

After this whole assault is over, the Vatican is going to have Rin and Yukio executed in secret. Nobody will ever know, and they'll chalk it up to the wounds Rin and Yukio received in their battle. I imagine they want to sever Satan's bloodline for good, Shura thought.

My brother and I are probably going to be killed any time now, we've served our purpose to the Vatican, Yukio thought.

Everyone knows he's going to die, everyone except Shiemi. I don't think any of us could bear to tell her, Ryuji thought.

I don't want Rin to die, but what can I do? Izumo thought as she shuffled her feet nervously.

I'm so glad he's okay, Shiemi thought.

It was like Rin was being bombarded by so many sensations at once, he felt the emotions of everyone around him but could hear their thoughts at the same time. His hands trembled as he dropped his father's sword, and he slowly turned around to meet the gaze of those he once called friends.

"Rin, what's wrong?" Yukio asked, as Rin looked back at him with a look of utter disgust.

"Am I just some pawn to you all? Is my life really worth nothing?..." he replied with a shaky voice.

"Rin, what are you talking abou-" Shura began, but she was interrupted by Rin, who pointed his sword at her.

"YOU! YOU KNEW. YOU KNEW THE VATICAN WOULD HAVE YUKIO AND I KILLED, AND YOU DID NOTHING!" he bellowed at her, his voice shaking the throne room.

"Rin, that's not true, if you just let me explain-" she began again, but she was cut off again.

"AND YUKIO, MY OWN BROTHER? You… would keep such a secret from me? From Shiemi?" he said, pointing his sword at his brother, who wore a stoic impression on his face.

"It had to be done, Rin… for the greater good." Yukio said, his voice unfaltering.

Rin couldn't believe what he was hearing coming from his brother's mouth. Shiemi wanted to speak up, to ask what the hell was going on, but she was unable to form words and remained silent.

"The greater good? What good comes from executing the two people responsible for killing Satan in the first place?!" he shouted.

"The Vatican needs Satan's bloodline exterminated once and for all. Only then can Satan be truly defeated. For that, I'm willing to give up my life. Shiemi didn't need to know, she would have told you and it would have hindered the mission's success." Yukio said in his robotic voice.

"Try to understand, Rin, none of us wanted this." Ryuji said.

"You're all just like Satan told me… you're all the same. I should have listened to my father when I had the chance. Look where playing the good guy got me." Rin said in an angry tone, his fingers tightening around the sword as he turned and walked backwards towards his father's throne.

"Rin, wait…" Shiemi squeaked out, but Rin wasn't listening to her, at least not in that moment. Taking a seat on the golden throne, Rin's ears elongated into their elf-like fashion, his flames burst from his body coating him in a blue aura as his attire changed as well. His black coat was replace with a traditional black yukata, and he examined his clawed hand, turning it around and smiling to himself.

"This is where I belong. Where I've always belonged. The successor to the throne." Rin said, looking back at his friends.

"I'm done being a tool used only to further humanity. Today marks the beginning of a new era, the beginning of my kingdom. I give you all a choice, as you were once whom I called my friends. Join me, or stand against me." Rin said, getting to his feet and drawing his own sword.

"Rin, you're making a mistake!" Yukio shouted.

"Silence, brother, you have heard my request. What will it be, all of you?" Rin replied.

"As your friends, it's our job to bring you down!" Shura shouted, drawing her own sword from the marking on her body.

"So be it. Before we battle, Shiemi, Izumo, come here. Surely you two will be staying, won't you?" Rin asked, as the two girls looked at each other.

"I…" Izumo started, her voice faltering and words failing to come.

"I've seen into both of your hearts, and even though you knew of my fate, you still wanted to protest, Izumo, but you felt that one person couldn't make a difference. I'll forgive you for that. Shiemi, you were unaware, and if you did know, you would have told me as soon as possible. Live with me here, in Gehenna." Rin offered, extending a hand to the both of them.

"They aren't going anywhere." Shura said, stepping between them. "They're my students, and they do as I say."

"I won't let you put them in danger any longer. If you take them now, I will have war." Rin said.

"Then war you'll have." Shura said, slamming the hilt of her sword against the ground and sending a cloud of smoke throughout the throne room as she grabbed Shiemi and Izumo's hands and ran down the hall.

"Come on!" Shura shouted, as her students fell in closely behind her.

"Demons of Gehenna! I am your new king, the son of Satan and the successor to my father! Do not let them escape! Don't hurt the girls!" Rin shouted, as the hordes of confused demons piled out the doors to chase them down.

"Everyone, this way!" Yukio shouted, shooting the hinges off of a door that led to the outside with his gun and waving the group forward.

"But, what about Rin?!" Shiemi shouted, tears streaming down her face.

"He's made his decision, you aren't safe here anymore. Come on, we need to get back to the gate we entered from." Yukio replied, grabbing her arm and leading her out the door.

End of Flashback

Rubbing her eyes with her sleeve and resolving to not think about her best friend until later that night, she went to work with her familiar, Nii-chan on treating their patient. Once they had done all they could, she moved onto the next wounded exorcist after the next until all of today's wounded had been healed to the best of their abilities.

"Alright, that's the last of them! Nurses may return to their tents until further notice." the supervisor shouted, and Shiemi washed off her bloody hands and returned to her tent to lie down. Hitting the bottom bunk with a thump, Paku slowly shuffled in a few moments after her and climbed onto the bed above her.

"Man, there's no shortage of wounded. I hope this war ends soon." Paku mumbled, and Shiemi replied,

"Yeah, I do too..."

"He hasn't contacted you recently, has he? I know he sent you a letter a few weeks ago." Paku said, and Shiemi gasped.

"How did you know about that?!" she said in surprise, but Paku merely shook her head.

"I could hear you crying in the middle of the night and reading it aloud." she said, and Shiemi just sighed and didn't say anything.

"You know, even if we are at war, he definitely cares about you. Izumo as well." Paku said, looking up at the ceiling of their tiny tent.

"What makes you think that..." Shiemi said, but Paku waved her off quickly.

"I mean, he sends you letters, leaves you tiny gifts that might be from him but you never know, and have you ever been injured on the frontlines?" Paku asked, and Shiemi shook her head.

"Of course you haven't, I'm sure you're aware he's ordered that you be captured unharmed, same with Izumo." Paku said.

Shiemi pondered her friend's words for a moment. In the three or so months they had been at war, Rin had sent her several letters, and just a week or so ago, had left her a beautiful bracelet encrusted with diamonds and all sorts of expensive jewels that glimmered in the sunlight. She actually happened to be wearing that same bracelet right now, but had it hidden under her sleeve to prevent any sort of suspicion arising.

"You know, Shiemi, I'm sure you and Izumo could convince him to end the war. Don't you think so?" Paku asked.

"Well, maybe. Still, that doesn't bring back anyone that we've lost." Shiemi replied.

"True, but I figure it's best to end it now when it's just getting started before it gets really ugly. The demons have only been attacking the borders that the Vatican has set up, but everyone knows Rin is holding back the true strength of his armies for one reason or another. Even if he is the King of Gehenna, he still has a fondness for human life, and he's not nearly as cruel as his predecessor. I've even heard that it's been ordered amongst the demon army that if the demons got past the border, the citizens of nearby towns were to be rounded up and given proper care instead of having their towns pillaged and burned to the ground. Rin isn't fighting this war to exterminate humans, he's fighting to get you two back." Paku said, leaning over her bunk to look directly at Shiemi, who was absentmindedly fiddling with her bracelet.

"Shiemi, are you even listening?" Paku asked, and Shiemi replied,

"Yeah... I just don't like thinking about Rin, that's all." she said.

"What? He loves you, he's fighting a war for you and all you have to say is that you 'don't like thinking about him?'" Paku asked in an irritated tone.

"I don't like thinking of my best friend as a villian! Even if he is fighting a war on my behalf, or Izumo's behalf, what makes you think I support him? He's murdering hundreds of exorcists every day, and because it's in my name, I'm supposed to act all enchanted by that? If that's his display of affection, it's sickening!" Shiemi shouted back, and Paku shrunk back into her bunk.

"... Sorry, Shiemi. I didn't think of it like that." she mumbled.

"It's okay, Paku, I know you didn't mean anything by it. It's just... I want the old Rin back. That's all I want." she said, reaching under her bed and feeling for the letter she had hidden inside her mattress. Pulling it out and unfolding the tear-stained page, she read it for what seemed like the millionth time in her head:

Shiemi,

Sorry it's been a while since I wrote to you, I've been swamped in responsibilities as of late.

It's awfully lonely in Gehenna, I've made a few friends but demons here aren't as pleasurable to talk to as the ones in Assiah.

I'll be sending Kuro with a gift in around a week's time, but try not to hold your breath, as it is hard for me to send him on long trips to your camp. I need him for company too.

I hate fighting this war, believe me, I wish our kingdoms could coexist in peace, I really do.

I've started my own garden today, it's not much but for Gehenna it's probably the prettiest thing for miles. Only thing that it's missing is you.

If you ever need to talk, go find the tallest tree in the forest near your camp, you know, the one with the robin's nest in it? I'll be there every day at sundown.

I love you, Shiemi. Please stay safe.

-Rin

Clenching the dirty piece of parchment in her hand, she shoved it back under her bed and began crying into her pillow again for her daily sobbing session. Hopping back down onto the ground from the top bunk, Paku comforted her friend as she cried heavily into her pillow, telling her that it was going to be alright when Shiemi knew it wasn't. As badly as she wanted to go to the forest at sundown and confront her friend, she wasn't one-hundred percent sure of Rin's true intentions. Would he actually end the war in exchange for her and Izumo? Is he as kind of a king as people claim he is? What will my life be like in Gehenna, which at first glance and having been there herself, didn't seem like a pleasant existence. She also knew that humans don't age in Gehenna, and unless Rin killed her, she's essentially stuck there forever.

However, she still needed to know. She needed to know whether Rin was a man of his word, and that he would stop this war as soon as possible. So, Shiemi waited until the sun began to set over the hills and the natural lights outside began to dim before she set off for the forest. Paku had fallen asleep shortly beforehand, much to Shiemi's relief. She didn't need to know where she was going, she worried enough as is. Checking to make sure no guards were looking her way, she set off into the forest and followed Rin's instructions, looking for the largest tree in the forest. Spotting a bright blue flower on the ground that glowed under the moonlight, she knew that she was getting close. Hearing the chirps of a robin, she spun her head around to see Rin sitting on a tree branch, looking away from her and off into the distance, which glowed brightly from explosions and fires of distant battles. He wore his same yukata that she had seen him wearing many months ago when they had been together in person, but he wore a simple gold crown on his head which she noticed was imbedded with sapphires that glowed softly in the darkness.

"Rin!" she shouted, and he instantly spun his head around to meet her gaze as his face lit up with excitement like a dog seeing it's master after a long period of time.

"Shiemi!" he shouted back, hopping off the branch and running over to her and pulling her into a tight hug, spinning her around in a circle as he laughed in between the mutual tears of happiness.

"I'm so glad I got to see you again. I'm sorry for getting you all caught up in my stupid wars." he said, apologetically, rubbing the back of her head softly as she held onto Rin for dear life.

"Dummy, why'd you have to go and run away from everyone..." she said quietly, sobbing into his yukata.

"I'm sorry for leaving you behind, I feel terrible for all the grief I've caused you the past few months." he replied.

"Won't you just end it now, Rin? Why go to such lengths for me and Izumo?" she asked, removing her head from his chest and looking up into his fiery blue eyes.

"True, I'd cross the world on foot to make you mine and Izumo is the only other person besides you that I can wholeheartedly call my friend, but being the king for the past couple months has given me a new perspective on the world. That's why I want you to be the one to help me, Shiemi, help me change the world for the better. As Yukio might have said, for the greater good." he said, and Shiemi noticed the particular venom in his voice when he brought up his brother.

"What do you mean? How could we possibly change the world for the better? We're just a couple of dumb kids!" she said, crossing her arms at her chest.

"Come on, instead of plaguing the world with violence and future wars between humans and demons, wouldn't it be better to... I don't know, coexist?" Rin said, and Shiemi uncrossed her arms and looked at him funny.

"Coexist? Come on Rin, even you know that's being idealistic. Demons and humans have been at war since the beginning of Satan's rule, what makes you think that we can suddenly drop all of that and act all buddy-buddy?" Shiemi said, getting a little annoyed at her friend.

"I know how it sounds, and it might seem unlikely and even impossible, but I have faith that we can compromise somewhere. The problem is that humans and demons alike are taught to hate eachother from birth, exorcists literally dedicate themselves to killing demons. How do you think demons respond to that kind of treatment?" Rin asked her.

"Probably not too kindly." she replied.

"Exactly. As you've witnessed with your own eyes, not all demons carry the same malevolence and destructive tendencies as others. Even the ones that are violent or destructive are only that way because they're conditioned to think like that. Under my new rule and the Vatican's authority, we can create a partnership between man and demon, forever changing our relationships as living creatures, both before and after death." Rin said, turning to face the distant moon which shone down on the two with it's bright and ominous light.

"Okay, okay... let's say that your idea isn't too crazy, and I agree to help you, where do we even start? We're at war. Demons and humans alike are out there killing each other all because you told them to, why would the Vatican listen to you?" she asked.

"You're right, Shiemi. The Vatican surely won't listen to me, they're much too stubborn and rely on the old world way of thinking. That's where you and Izumo come in. You two will be the harbingers of peace and the humans that united the two warring kingdoms and brought a new peace to the world that has never been achieved. Then, we can finally be together." Rin said, turning back around and taking her hand in his. It was very warm, and it felt marvellous on a frigid and cold night like this one.

"You know, if you asked me to come back with you, I wouldn't refuse. We could be together for the rest of eternity, in Gehenna." she said quietly, pulling her scarf up to cover her rosy cheeks.

"Yeah, we could. However, that would make me as greedy as my father and as selfish as the Vatican. I want to be together with you in a free world, a world devoid of prejudice against race and a world where both the yin and yang can exist in perfect harmony. That's the future with you that I desire, Shiemi." Rin said, looking deeply into her eyes.

"You've really changed, Rin... I didn't think I would ever hear you say something so selfless." Shiemi said honestly, and Rin nodded in reply.

"Being a king can be a burden, but it's opened my eyes, and that's a good thing. I don't desire to rule a kingdom of bloodthirsty creatures from Hell, I want a true balance and peace that lasts as long as I remain King, with you as my Queen." Rin said, taking his hand and putting it on her cheek as he leaned in to kiss her deeply. Shiemi had to stand on her tiptoes to reach his lips, but he held her tightly as they both released their pent up desires and angst in that one moment. Rin tasted intoxicating to her, like the ashes of a fire that made her mouth dry but quenched her thirst at the same time. Pulling apart and leaning against her forehead, Rin smiled at her and brushed a strand of hair from her face, suddenly taking his tail and tickling her nose with the tuft of fur at the end of it like he had done so many times in the past, causing her to giggle like a schoolgirl.

"I wanted to give you this a couple days ago, with it being your birthday and all, but you know I can get busy sometimes. Sorry." he said, pulling out a tiny box from nowhere and holding it in the palm of his hand for her to take.

"Oh, thank you so much, Rin!" she said, taking the box from his hand and removing the ribbon tied around the little box. Opening it, she pulled out a small hair ornament in the shape of a pretty blue flower which, like Rin's crown, glowed softly in the darkness.

"A hair ornament?" she asked. Not that she was ungrateful by any means, but it seemed like an odd gift for Rin to give her, of all people.

"Well, I know you have to keep stuff like this inconspicuous, but I thought it was something you could play off without getting too many questions about where you got it. Besides, it's not just any old hair ornament, I've enchanted it with my flames so that you can always feel the warmth of my fire, no matter where you are. Plus, it's got a couple of other functions, but I'll let you figure those out on your own. It's more fun that way." he said, flashing his boyish grin at her.

It's strange, he's matured so much in just a few months, but his smile never ages, she thought.

"Thank you so much, Rin. I... I love you." she squeaked out, and Rin smiled back at her.

"I love you too, Shiemi. Don't ever forget that." he said, giving her one last hug before he left for Gehenna.

"Wait, Rin, where is Izumo? How do I get to her?" Shiemi called after him, and he stopped and half turned around, saying,

"That's all for you to figure out on your own, Shiemi. This is your journey, not mine. If you're gonna be a Queen, you gotta learn to be resourceful. See ya later!" Rin said, but before Shiemi could protest his departure, he disappeared into a cloud of blue smoke, leaving behind the faint smell of ashes.

"Jeez, he never did like to do things the easy way..." Shiemi said with a pout, but she couldn't help the grin that crept onto her face as she looked down at her new birthday present. "I love you too, Shiemi. Don't ever forget that." The words echoed in her head over and over again, she honestly didn't believe Rin would ever return her feelings or even say that he loved her in the first place. Knowing that she held a special place in his heart made her feel warm and fuzzy, and she placed the radiant blue hair ornament on the side of her head. She didn't think that blue would clash well with her blonde hair, but upon further inspection of her reflection in the screen of her phone, she quite liked the new look.

Creeping back to her tent from the forest, she surprisingly made it back into camp undetected, tiptoeing into her bed underneath a sleeping Paku. Removing her precious hair ornament, she placed it under the bed with her letters and other gifts from Rin as she sighed and rolled over to face the wall of the tent.

You're just as crazy as ever Rin. Only you could come up with such a plan, demons and humans coexisting. Still, it would be nice if everyone could just get along... she thought.

Was his idea really that outrageous? Although Shiemi figured both sides wouldn't cooperate at first, she couldn't ignore how confident Rin was in his own words. He really believed such a reality was possible. He was a little young to be a king of anything in her opinion, but Rin could really manipulate people's hearts when he wanted to. Even if the war had taken a toll on all exorcists fighting in it, she still wouldn't have wished any other alternative. Had Rin not stepped up to rule over Gehenna and keep the demons under control, there's no telling what could have happened to him or Yukio, and the demons were sure to launch a counter attack on the humans at some point.

Yukio popping up in her head, Shiemi realised she hadn't spoken to him since before the war started. While they were friends and remained as such, she loved Rin and only Rin, and Yukio's actions as of late greatly displeased her. He hadn't bothered to stay in touch or even write to her while they operated from separate camps along the border, and the last time they had spoken in person, he acted cold and distant. Shiemi was no mind reader, but she figured Yukio blamed himself for forcing Rin into his current situation, and effectively, causing a war in the first place. While Shiemi at least thought Yukio still cared for his brother, she had to admit that she found it disgusting she would have kept their joint execution a secret from him. The Vatican really did use Rin like a tool, not stopping for a second to consider his feelings or that he was human in the slightest.

With her other friends, keeping contact wasn't avoided but more unable than anything. They hadn't been informed of where they had all been shipped off to, and her friend Paku just happened to end up in her camp, which was one among dozens. What were the odds? She did dearly miss Izumo, and even her other friends a little bit, but like Izumo, she had no idea where they were stationed.

Couldn't I just ask Rin? I mean, he's the King of Gehenna, I'm sure he has eyes everywhere, right? she thought. Rin did say the hair ornament had a number of different features.

Pulling it back out from under her mattress, she fiddled with her hair ornament, trying to get it to do something. Giving up after a few minutes when she pricked her finger on the sharp edge of the glass blue rose and her blood trickling onto the ornament, she returned it to it's previous place under the mattress and laid her head down on the pillow. I'll figure it out tomorrow, she resolved, closing her eyes and drifting off to sleep.

The Next Morning...

"Shiemi, Shiemi, Shiemi, please please please wake up!" Paku whispered frantically, shaking her repeatedly until she stirred from her slumber.

"Paku, what is it..." she mumbled, irritated and sleepy.

"Your tail. You have a... tail." Paku said in an urgent tone, and she jolted awake and sat up at the speed of sound, turning her head to face her backside and sure enough, she had a black tail with a poof of fur at the end, just like Rin.

Oh no.

Well, what did you guys think? I'd love to hear what you liked or disliked about the story, I'm really looking forward to continuing this story and I hope you're all eager to keep reading! Cheers!