Author's Note: Hi there! I haven't written anything in a few months so while I work on getting back to an organized routine, I decided to try something a little different. I don't expect many people to be interested in this, but I wanted to post it anyway because…I don't know. There's a lot of focus on fan characters (OCs) so here's your warning if you don't like those types of stories.

Blue Exorcist belongs to Katou Kazue and Co.

...If we are lucky, then by the time you read this, I am dead.

Heh, I've always wanted to write that unironically.

By now I'll assume you know everything there is to know about Gehenna and Assiah, so I won't bore you with any petty details. I guess I'll try to explain myself here and hope that you'll understand why I had to do the things I did.

Let's see… Where to start…

Growing up, I always wanted to be the hero. When we played pretend, I was the knight in shining armor, the ruffian helping the poor, the sympathetic king—I made it my goal to vanquish the monster. Sometimes that monster was a huge dragon that spewed acid. Other days it was a greedy tax collector and his hired swords. And, more often than not, it was a human, an exorcist, the paladin, et cetera.

But we don't really think about the significance of these things as kids, do we?

In spite of my adventures as a child, I never harbored any hatred towards humankind. I never wanted to massacre them, or claim Assiah as my own, or continue this pointless war we've been fighting. None of us did.

Assiah was always seen as a paradise to us, a sort of 'grass is greener on the other side' thing. It was a prosperous, beautiful place where we thought we could be free from the everyday struggles of life in Gehenna. Perhaps I was a little too eager to believe in this, too determined to hold onto my childish fantasies, too afraid to face the truth.

I honestly believed that we could all find peace if we worked hard enough. That, one day, we would be forgiven and our two worlds, as different as they may be, would finally be combined to create a place where everyone, demon and human, could live in peace. No more hiding. No more running. No more death. Demons would no longer fear humans, and humans would no longer fear demons.

That was all I wanted. Innocent enough, right?

But I was stupid. I was so very stupid and too blinded by my ambitions to see the trap I had so plainly walked into.

This… All of this… It's my fault.

I'm so sorry.

. . .

SMACK

It hurt. It hurt more than anything he had ever experienced before.

No, not his cheek—but that did sting a bit.

It hurt knowing the only man he ever saw as a father was abandoning him. All because, (thanks to that horned punk), he was no longer considered human.

"There's no time to argue." Father Fujimoto's voice, uncharacteristically saturated with urgency, snapped him out of his stunned state. "Now do as I say!" The old man gestured angrily to the bag and sword Rin had carelessly tossed aside.

He lowered his eyes, regretful of the hurt he had caused his father, though his pride would never let him admit this aloud. "...Fine." He hid his emotions behind a scowl and slowly gathered his things off the floor. Rin told himself he wouldn't do it, but, as he entered the hallway and left his childhood room, he turned to look back.

Father Fujimoto remained where he was: fists clenched hard at his sides, eyes staring solemnly at Rin's empty bed under the window. He didn't want to leave like this, and almost went back to apologize, but before he could muster the courage, the priest raised his head and grinned at him. "You still here?"

That familiar expression tugged at his heart, so hard it made angry tears rush to his eyes. How could he? He was acting as if nothing had happened, as if Rin hadn't just screamed at him for being a lousy parent. Furious, he opened his mouth to shout one last insult, to let the old fart know he would be back to repay him for that slap across the face, but he was silenced as someone—no, something—came crashing through the window beside Father Fujimoto's head.

With a startled shriek, Rin fell back, horrified when he recognized the horned demon from earlier. He crept forward on all fours, ignoring the broken glass scattered around him. A thick, furry tail whipped wildly behind him and a long, pointed tongue hung out of a mouth lined with impossibly sharp teeth. "Stop running away and listen to me!" His voice was oddly deep for his boyish appearance—like growling interspersed with grunts.

The sound only frightened Rin more. "G-get away from me!" He scrambled back, desperately swinging his sheathed sword in frantic self-defense.

"Stubborn little shit, aren't you?" Fujimoto wrapped an arm around the demon's flailing tail and smashed the heel of his boot into the back of his head, rendering him immobile for a brief moment. It gave him just enough time to snap at Rin. "Don't just sit there—go!"

"B-but...!"

"Go!"

Responding to his father's demanding tone, Rin clambered quickly to his feet and ran. "Wait!" The demon thrashed violently under Fujimoto's grasp. When he realized he wouldn't be getting away that easily, he twisted his body and narrowed his eyes at the priest in a vicious glare. It was clear he didn't like being beaten—even when his opponent had an obvious advantage. Fujimoto grinned at the displeasure in his face and raised a hand, preparing to say those dreadful words all demons of rot seemed to hate. Before he could open his mouth, the demon snarled and lunged forward.

They went tumbling to the floor together. Fujimoto expected the sudden crash of force in his chest, the small shards of glass biting through his clothes, the ache as he landed on his back; but what he didn't expect was a few swift, hard punches against his lower jaw. It left him in a daze, allowing the demon to escape and chase after Rin.

"Damn…" he whispered, struggling to pull himself to his feet. Fujimoto hadn't been hit that hard in quite some time. It felt good to know he could still be brought down.

He brushed off the pain enveloping his body and staggered slowly to the door. Rin couldn't have gotten far. If he hurried, he could catch up to the two and save that possessed boy from his attacker, (again). But, just as he reached the doorway, he hesitated. A cold, overwhelming sensation passed over him—someone was watching.

"Who's there!?"

A large, white nagaraja, its top half decorated with sporadic, black spots, appeared in front of him, blocking his path. It raised itself to his height and flicked its tongue curiously. "I hope you'll forgive me for my tardiness, Father. I'm not familiar with this area." Unfazed by the snake's daunting size, Fujimoto casually turned back to the open window.

A young demon lithely stepped over the broken glass as he entered the room through the window. He was dressed in a plain, brown uniform and wore a strange, thick, white cloak over his shoulder, concealing the entire left side of his body. The boy appeared unusually human save for the slightly pointed ears, the long, furry, green tail, and the tiny fangs poking out from the corners of his smile. But the demonic traits and oddly mismatched cloak wasn't what initially caught Fujimoto's attention—it was his hair. It had two distinct colors: black on the bottom and a light shade of green on top, separated by a jagged line that seemed to wrap all the way around his head. Atop his hair sat a familiar, upright spike that leaned slightly to his left.

Fujimoto squinted his eyes and rested a closed fist under his sore chin. "King of earth? You look...different. Did you get a haircut?"

He politely covered his mouth with a hand as he laughed. The priest noticed he had a kind face, (rare for a demon), with wide, brown eyes and round cheeks. "Amaimon is my father. Don't worry—you're not the first person to make that mistake." He spoke with a soft smile, trying to make light of the subject. At that moment, Fujimoto was reminded of how much he hated demons that took the appearance of humans. "My name is Ammon. It's a pleasure to finally make your acquaintance, Father." He bowed slightly and the nagaraja, (apparently his familiar), mimicked his movements.

Fujimoto somehow found himself appreciating the boy's attitude—it wasn't everyday you met a demon with manners. But, regardless, he was still a demon, and no amount of ass kissing would change that. "Nice try, kid." He snorted and crossed his arms.

Ammon immediately straightened his posture, brow scrunched together in a perturbed manner. "K-kid?..."

"Look, if you're here for your friend, you just missed him."

That repulsive smile returned to his face. "Oh, actually, I'm here to keep you busy while Astaroth retrieves the prince." Fujimoto's sardonic mirth darkened significantly. Before he could snap a response, the demon threw his cloak over his shoulder, revealing a black scabbard at his hip and a complex, matching gauntlet on his left hand. "We can't have you causing any more interruptions."

"Hah!" The priest gave him a disdainful smirk. "You're going to kill me?"

Ammon frowned deeply and lowered his gaze, an expression that made him seem more human than demon. "I'm sorry," he whispered softly, fidgeting with the jeweled hilt of his sword. "I don't want to...but I can't refuse an order from my superior." He drew his weapon from its sheathe with one quick, practiced movement. "I'll make it as painless as I can."

He instantly knew the sword was not made from human metal. Its blade was a deep, translucent purple and sparkled like the night sky under the slanted afternoon sunlight that poured in from the broken window. The longsword cast a beautiful, violet shadow around them as the demon shifted into his fighting stance.

Fujimoto tossed his head back and laughed. He had nothing that could counter such a splendid weapon and, for some reason, he found that funny.

. . .

Finally realizing he was no longer being pursued through the maze-like collection of alleyways, Rin slowed his panicked pace until he came to a stop, desperately trying to catch his breath. His chest burned, his legs ached, his blood thundered in his ears, and, worst of all, he couldn't shake the feeling of guilt for leaving Father Fujimoto to deal with the demon alone.

Not like he could do anything about it now—the old man made it clear that he was to leave and not come back, lest he put everyone at the monastery in danger.

With a heavy sigh, he tucked the sheathed weapon into his belt, shoved his hands into his pockets, and continued walking aimlessly.

Now what was he supposed to do? How was he going to afford food? Where would he go when night came? …Wait, didn't Fujimoto mention something about a phone?

Rin froze and mentally smacked himself. My bag… He must have left it behind in his old room when the demon chased him out of the church. Just great. Now he didn't have a choice but to go back for his things. Maybe… Maybe if he was quiet enough, he could sneak in and convince one of the priests to let him stay without telling Fujimoto, (at least until he got a job and a place to rent.) He figured it was worth a try, even if he would just be chased off, and turned to retrace his steps.

And froze.

Barely a foot away from him stood the horned demon. "Hey." The demon's voice had lost its vehement anger—enough for Rin to pause and give him an incredulous glare. "Uhh...sorry about earlier. It wasn't my intention to frighten you…your majesty." Coal tar emerged from the corners of his mouth like black smoke, happily twirling around his head before floating away. Rin took a few cautious steps back, his heart pounding loudly in his ears.

"Wh-what do you want f-from me?" he asked, failing to keep his voice steady.

"We need you to come back home with us and take Satan's place," he explained calmly. "Gehenna needs a king," he continued in response to Rin's bemused expression. "Our people are starving and demanding retribution. You're the only one who can claim his throne, the only one who can save us, blah, blah, blah—the usual 'chosen one' shit. Let's go."

"Huh?..."

He shook his head once, frustrated with the prince's lack of understanding. "The Lord Commander can explain it better." He reached out his hand, palm up, but Rin immediately cringed away, as if the gesture hurt him. "What?" He tilted his head and raised a brow at Rin's reaction.

"I… I'm not going anywhere with you!"

He huffed, offended, and dropped his arm. "Look short stuff—you inherited Satan's flames. By correlation, you also inherit his throne. Now hurry up."

Rin turned to run and was met by a pair of dogs—their flesh rotted and the ground at their paws scorched black. He hesitated, realizing he was trapped. With trembling hands, he fumbled to remove his sword from his belt. The two snarled at the weapon as he held it up, black, steaming slaver dripping from their open mouths.

"Don't make this harder than it needs to be, your majesty." The white-haired demon had a hand raised, preparing to release control of his death hounds. "I will ask you once more: come along quietly."

Despite the cold fear that trickled down his spine, Rin grinned at the demon. "Fuck you."

Just as he was about to unsheathe his blade, Father Fujimoto's voice returned to him. Never draw this sword! If he broke the seal, he would lose any trace of humanity he had left. Was this truly worth the risk?

That split second of uncertainty sealed his fate.

. . .

Ammon impatiently tapped his foot as he waited for Astaroth in their agreed meeting spot: a secluded clearing in a nearby forest. Assiah was beautiful this time of year, and the king of rot's tardiness allowed him the time to admire his surroundings. Thick, white clouds floated lazily along a blue sky. Long, thin shafts of sunlight poked through the leaves above him, shifting and dancing wildly as a breeze rustled the trees. His heart sank as he realized the people of Gehenna had never experienced something so tranquil before.

And then, the serenity of the park faded and Ammon's anger returned.

"Grr! What's taking him so long!?" He directed the question to no one in particular, but his nagaraja, Shesha, let out a hiss that seemed to match his master's disapproving tone. "He better not be sightseeing," he growled, apparently responding to something the snake had said. "We have a tight schedule—he can fool around later!"

As if on cue, an obnoxious, loud shuffling indicated the demon's arrival. "I have him."

"There you are. I-" he stopped when he noticed the condition of their prince. Rin had fresh bruises on his face, a large tear on his right sleeve, and a bleeding nose. Astaroth ushered him forward, tightly holding the prince's hands behind his back. "What did you do to him!?"

"He's here, isn't he?"

"I told you not to hurt him!"

"I don't remember that."

Ammon sighed and shook his head. Neither of the two demons expected Rin to come along quietly, so perhaps it was best he remain restrained for now. "Well… It's a pleasure to finally meet you, your majesty. I am Ammon." He bowed deeply with Shesha at his side.

"What do you want with me?" he asked in a growl, attempting to hide his fear.

"We've been looking for you for a long time, Rin—we're here to bring you home." He smiled at the prince, his tone light and benign. "Your biological father—Satan—was assassinated shortly after you were born, and, now-"

"Wait, wait, wait. Did you say…Satan was killed?"

"Yes."

Rin's face scrunched up in disbelief. "Satan…the god of demons…was killed?"

"I trust the concept of death is not foreign to you?"

He brushed off the demon's sarcastic remark. "How?"

"We don't know what took place or who committed the crime," Ammon explained coolly. "Lord Satan was weak and took to bed. He was found murdered in his throne room a few days later." He rested a hand on his chin as he continued to mumble in thought. "It could be that he invited someone he trusted into his personal quarters never knowing they would turn traitor…but, then again...that doesn't add up with-"

"Ammon," Astaroth snapped him out of his reverie, "you're rambling."

"Oh, uhh... A-anyway, what's done is done. Now, we need you to take his place as king."

"W-wait!" Rin struggled weakly against Astaroth's grasp. "Why me? Can't one of you be king!?"

"It's not that simple." Ammon turned away and lowered his eyes, watching the long grass as it swayed with the wind. "You are a symbol of hope for our people, Rin."

"What…what do you mean?"

"Yuri felt that humans and demons could eventually learn to coexist, and Satan shared her views. You, and consequently your brother, were born from that compassion, a unique desire to see our two worlds united as one. Shiro, of course, didn't agree, and kept you ignorant of your demonic heritage…until now, that is." Ammon turned back to Rin, a soft smile on his face. "So, you see, not just anyone can be king. We need someone who represents unity between Gehenna and Assiah: you."

"I don't understand."

"That's to be expected. Things will become clearer as you explore the Infernal City and its Octants." Ammon threw his cloak back and drew Nightbringer. He drove her blade deep into the earth, summoning the same Gehenna Gate the two had used earlier that week. Heads and arms began to form the center of the portal, eagerly grasping for victims to pull into the void.

Rin kicked and flailed against Astaroth as the tar from the Gate continued to bubble and take shape. "N-no! I don't want to be king! Let me go!" In all honesty, Ammon understood Rin's reluctance—it was never pleasant going through the Gate, (even for a high-level demon like him). But it was, unfortunately, the only way to travel between the mirrored worlds.

The Lord Commander stepped back, allowing Nightbringer room to work, and placed both hands on the prince's shoulders to calm him. "I know it doesn't look like a fun ride, (and it's not), but I promise it won't take long." Rin shook his head quickly, kicking at Astaroth with far more fervor than before. "Rin, please try to understand! Gehenna needs you. Without someone like you to take the throne, we'll," Ammon paused to swallow his building emotions. "Without you, all of our people will die."

"That's not my problem!" he spat, shooting Ammon a vicious glare.

"Well, at least he inherited Satan's ferocity." Astaroth failed to hold back a small, sarcastic laugh.

Ammon gave the demon king a disquieting glance before turning his gaze to Rin. "All I'm asking is for you to come see the world your mother wanted to save with your own eyes." Those words seemed to strike a chord; Rin stopped struggling and looked up.

"M-my mother? What do you know about my mother?"

"I'll make a deal with you. If, after you see what lies beyond that portal, you still have no interest in becoming king, then I will personally escort you back to the monastery. And you will never see or hear any of us again. Agreed?"

"Ammon, you can't be serious!" Astaroth jerked the prince to the side slightly, wrenching him from the commander's grasp. "After all the trouble we went through to get him! You would just throw all of our efforts away!?"

"There's more to it than that, Astaroth," he snapped. "He won't make a good king if he doesn't have the motivation." The demon grunted angrily, but said nothing more.

"Promise me. You promise me that you'll bring me back." Rin eyed him with uncertainty.

Ammon placed a hand over his heart and bowed, a display of respect. "I swear it, my prince."

"…Okay. I'll go. B-but only because I don't have anywhere else to go! Not because I want to!"

He chuckled. "Of course. Astaroth, if you could please escort Rin to the Gate."

The white-haired demon obeyed and urged Rin forward. He stopped short of the fully formed Gate and hesitated, watching the creatures writhe with disgust. After a moment, he roughly shoved Rin into the black sludge. He cringed and squirmed as tiny, black arms wrapped around his legs. "AHH! What is this!?"

"It's part of the fun!" Ammon crouched beside him, a playful smirk brightening his face. "Keep your hands and feet inside the Gate at all times. Oh, and keep your mouth closed if you can. Trust me, you don't want to taste that stuff." He winked and pushed Rin down until he was completely swallowed by the void.

Ammon moved to stand beside Astaroth, who backed away instinctively. "Uhh... I'd love to go with you, Ammon, but it just so happens I have a one-way ticket for the 'nope-train' to 'fuck-that-ville'."

He laughed, amused by the demon king's uneasiness. "Actually, I want you to stay here and keep an eye on the other Okumura twin." He produced a bundle of forms and instructions from inside Nightbringer's sheathe and handed them to Astaroth. "You'll be attending True Cross Academy, but not as a full-time student. Yukio is teaching a first-year exorcist class and you'll be joining as a 'page'. You'll be among other exorcists—both young and veteran—so try not to draw attention to yourself. I know we don't always agree, but I don't wish you ill, Astaroth."

"Yeah, yeah, yeah." He dismissed Ammon's words with a wave of his hand. "I'll be fine. But…" he paused, skimming through the pages, "what about Mephisto?"

Ammon turned his head to hide a scowl. "He is no longer involved with Gehenna's affairs. If he tries to mettle in our business, the Order of Angels will respond accordingly. For now, just stay away from him and don't provoke him."

He nodded in acknowledgment and tucked the pages under his arm. "Good luck with the prince. It doesn't seem like it'll be easy to work with him."

"Don't worry—we'll find a way."

"Oh, wait... Here." Astaroth held out the sword he had been using as a walking stick. "The boy had this with him. He might want it back."

"A katana?" He accepted it with a raised brow and tucked it in his belt behind Nightbringer's larger sheathe. "Tiny thing, isn't it?"

The demon king shrugged. "I wouldn't know—I don't need weapons."

"Don't rub it in, Astaroth." Ammon bid him farewell as he made his way to the center of the waiting Gate. "Enjoy your train ride. Come, Shesha." He pulled Nightbringer from the ground and returned her to her sheathe, successfully severing the connection between the two worlds. Slowly, it disappeared, taking the Lord Commander with it.

Astaroth remained standing in the forest's clearing even after the Gehenna Gate had completely dissipated. He turned his gaze upward, watching the clouds creep by. It seemed so peaceful up there.