Before you start reading, you have to know something. This story may contain some things that are not actually true and do not follow the anime/manga. (And, well, it's AU, so there's going to be a lot that doesn't follow canon, but I'm saying some of the facts presented in there.)

The idea popped into my head when I first watched the anime, and I always wanted to write it, even after reading the manga and finding some stuff that didn't go along with my AU. So. Please do not review and complain about information being wrong, the story being stupid, etc. It's AU.

With that said, please enjoy. This is being posted quite spontaneously, so I may or may not continue it.

Disclaimer: I don't own the amazing Ao no Exorcist.

…

The black metal glinted deviously. My breath caught as I stared at the dangerous weapon, leveled at my chest with a practiced ease. This wasn't something I'd imagined could happen—at least, from the current individual in front of me. It had certainly happened before, probably far too many times to be normal, but all those times they'd been my enemies, to a certain extent. The teenager in front of me…was my twin.

My twin, Okumura Yukio, younger than me by a mere couple of minutes, was pointing a gun at me, ready to kill me out of not a sense of justice, but a sort of revenge—revenge for his innocent father's death. And in his eyes, I'd caused it.

"Don't you dare point a gun at your brother," I growled angrily, noticing blue fire lit upon me. What was wrong with him? I could see through his still, blank façade—he was scared of what he wanted to do, but he was so, so willing to go through with it anyway. He wanted everything to return to normal, where I was clueless about my nature, and his amazing father, not to mention his role model, was not sent to forever stay six feet underground. But then, that wasn't possible, and he saw another reality through this choice: if I was shot and killed; if he could simply get rid of me, then he would not be reminded of his relation to a demon—the son of Satan, at that—and he could continue on with his job as prodigious exorcist, teaching exorcist classes while being swooned over from all the girls in his classes. He could mourn his father's death quietly, without a twin brother he blamed his father's death on to barge in and disturb his peace, and he could move on without any more burdens.

But we were currently in the midst of an unexpected battle. As a huge, teeth-baring hobgoblin rippled in the air, forming into existence, I drew my sword and lunged for the demon looming over my little brother's shoulder, while at the same time, Yukio's eyes twitch of the finger—a shot, fired—a screech from the dying demon I'd sliced in half—pain, terrible pain pulsating in my chest—

I found myself with a broken sword in my hands as it slammed harshly into the tiled floor, cut fingers dribbling thick, red liquid as I lay in a puddle of the same blood. A shuddered breath escaped out my lungs as I felt my body fight for life.

Careful hands were tugging at my arm, and I saw white for a moment as Yukio flipped me onto my back and I gasped, hands spasming as I attempted to reach the literal hole in my chest.

"Rin, oh God, Rin—I'm sorry," he said, voice trembling, and it was the first time in a long time that I heard that fearful, shaky voice—the voice that Yukio had often had as a child, afraid of the demons I had been unable to see.

I didn't want to blame my brother. I didn't want him to live with guilt, and so I reached up with a bloody hand, eyesight blurring at the strain, attempting to touch his cheek and give him a small smile before a last sigh escaped me, and my soul—if I had a soul—left this body.

…

"Gughhhhh," I gurgled, lungs breathing in an arid, but rather clear, air. Where was I? Eyes blinking open, I found myself in a completely different landscape than just a couple moments before. I thought of sitting up, and I was suddenly sitting up—the body I currently possessed appeared to be flexible and strong, tough and fluid. Even so, I was gasping for breath, still adjusting to my new body.

And then I thought. I knew that I had died. And dead people either went to Heaven or Hell. Er, Gehenna, as it seemed to be. Then was this Gehenna? Because this was, quite obviously, not Heaven.

…Well, I was the devil's son, after all. I couldn't really have expected to go to Heaven.

Strength felt to have returned to me, so I leaned forward—and my knees and spine immediately, easily, straightened—I was already standing firmly on my two feet. I brushed off the seat of my pants with an automatic gesture, taking in my dark surroundings. Well, maybe not necessarily dark—there were red fires burning sporadically on the rocky, scarred terrain: some tiny candle flames and others enormous bonfires triple my height. The sky, a rusty, dry-blood hue, flashed with random images. I watched for a moment, eyes widening at them—they were of Assiah!

There was one of soldiers fighting: the Americans in ragtag farming clothing, hiding quietly behind the natural shrubbery and waiting to ambush the orderly British soldiers marching their way. Another was of a young girl shrilly arguing with her parents, upset that she wasn't allowed to visit her friend's house. And another, where normal civilians perused racks of vegetables, fruits, and meats in an average grocery store, chatting amiably or glancing at grocery lists. My eyes kept darting back and forth between images that appeared and disappeared, and I finally glanced away, head swimming. What did this mean? Was this how demons learned about Assiah and its peoples' customs, through these…images of history or average day-to-day events?

Was I supposed to sit here and watch them, then? Was this my punishment for being the devil's son—to watch images of Assiah, forever desperately wishing I could be back there?

I shook my head. That was ridiculous. Both the idea and that dramatic sentence. That was…not going to be my fate, as cheesy as that phrase sounded too. I was going to get out of here—unless you're supposed to stay here, a little voice told me. I scowled. Glancing around, I searched for something, anything, that could get me out of here, and a small, black object floated in front of my vision. Swatting it away angrily, I watched as it landed on the writhing ground and broke apart. Wait—writhing? With a morbid fascination, I bent down, absentmindedly noticing the pulsing underneath my feet as I watched body parts packed tightly together squirm in the ground. I flicked the head of the little black object I had swatted, and it landed a distance away, attaching itself to a thin, wiggling string and floating up, once again, into the air.

Repulsed, I backed away, straightening up again as I shook my head. I was going to get out of here, and fast. Gehenna was the creepiest place I'd ever been—but then, I suppose that must've been expected.

With a twist of my heel, I turned away—simply to run directly into a hard, tall, and thin boulder. I rubbed my face, glaring at it as if it was sentient, before stepping to the left and attempting to walk around it.

…Well, it was sentient after all, seeing how it had appeared in front of me again.

"Wh-whoa!" I stumbled backward, eyes focusing on it and watching as it brightened—in reality, my eyes probably adjusted to the darkness—only for a very familiar face to appear.

"Mephisto?!"

He smirked. "Hello, Rin."

I blinked. He looked different. Very different, I realized, as I stared at his dark, dully-shining liquid-like clothing, molded around him but appearing much bulkier than a simple cotton shirt and pants—it was a little like armor. Liquid armor, then.

I shook my head. Now was not the time to be concerned about physical appearances, but then—

"Wait, what are you doing down here?"

He simply smiled, hovering slightly above the ground, causing his tall, slinky body to appear even taller.

"…You have wings?"

I realized that maybe physical appearances were quite important after all, as I noticed a slinky, dark purple rope-like thing whipping into view. A tail much like mine, only different in color. He finally chose to set himself down on the ground, large, leathery bat wings slowly folding in upon themselves.

"I think I could say the same about you, too, dear little imbecile."

I narrowed my eyes. I didn't know what that last word meant, but it sounded like an insult. Then I realized what, exactly, he'd said, and my eyes widened involuntarily as I reached backward, hands grasping at…at a thin, sensitive membrane. The sensation was quite the stimulus, as if the nerve-endings there were a hundred times more sensitive than any other part of my skin. The finger brushing the wing jerked away from it, and I subconsciously jerked the wing back too, beyond startled.

Mephisto tsked, grabbing my attention again. "Rin-kun, I would've thought you'd realize it by now."

His eyebrows were raised above sinister, fire-pupiled peridot eyes. I stared, and compiled everything I'd just noticed about him.

"You're a demon!" I accused, belatedly finding my statement quite obvious. "Then what are you doing playing exorcist headmaster?"

The demon only smirked. "Assiah is my chess game, little brother. And all of you are my chess pieces."

I wrinkled my forehead. That didn't make any sense at all. He was playing chess with us? Then…who was he playing against?

"You called me 'little brother'. What's that supposed to mean?"

"What do you think? Surely not from your mother's side, as I'm centuries old. Far greater than that, even."

"You're…you're Satan's son too?"

Mephisto threw his head back and laughed at that. I didn't see what was so funny, and chose to say so.

"Rin," he snickered, "why do you sound so surprised by that? Surely you didn't think your mother was the only woman who chose to involve herself with Satan."

My eyes widened. "You're…like me? What—who are you?"

"Ah." Mephisto spread his hands, claw-tipped fingers gleaming from the bright fire. "You finally asked, and although I was planning to inform you of this at a later time, I suppose I cannot delay this conversation any longer. I am Samael, King of Time and Space."

He paused for dramatic effect. "There is a hierarchy of the Eight Demon Kings, the Baal, with Satan above us all ruling over the entirety of Gehenna. I am second in this hierarchy, unfortunately. We are all Satan's children. So you could say...we're all your brothers."

My head reeled. I had eight half-brothers?! Not to mention the fact that they were all the Hell Kings…

"Okay…I'm asking about that later. Right now, I want to know what I'm doing here. Am I dead?"

"Ha! Dead!" The demon king guffawed. "No, you are not dead. You are very much alive, Rin. In fact, you are now a full-blooded demon—and your human body is waiting for you to claim it again.

"When your demon heart is un-sealed, or if it was never sealed in the first place, then it is guaranteed that, as a half-demon, you will live out your human life however it may go, and then continue your existence as a demon for eternity. For quarter-demons or less, it is slightly different, as they have less of a chance than half-demons in immortality, but that's something better left for later. In your case, when you broke your sword, Kurikara, your demon heart should have flown into your body and become a part of your soul. However, your human counterpart was dying at the time, and so it chose to materialize down here, waiting for the moment your mind and soul left Assiah to travel down to Gehenna. Most likely, your demon body was attracted to the soul and mind it had become familiar with, trapped in the sword as it was, and your soul and demon body 'combined' for your revival as a demon."

His hands, from where they were poised in the air to create quotation marks, settled back onto his cotton-candy cane, looking out of place in the dark and gloomy land of Gehenna. It was surprisingly standing up without support, but when I peered closer at it…well, not-so-surprisingly standing up on its own, then. It was a demon itself.

"I—"

The prospect of immortality was daunting. I couldn't completely wrap my mind around it, what with everything that had happened in the last couple of minutes.

"Alright, fine. I'm going to live forever. No big deal. I need to deal with the present right now, and you're going to tell me how to get back."

I glared at him. He was taking amusement out of everything he'd told me and my reaction to it all, and damn it if I wasn't going to at least get some real help out of him.

He chuckled. "My, my, you're a little feisty today. Alright. Close your eyes, then."

I closed my eyes uncertainly, choosing to keep one slightly cracked open in case he tried something.

"Ah-ah, all the way."

I acquiesced, disgruntled.

"Visualize yourself in Assiah, at True Cross Academy. What we need you to do is return to Assiah by possessing a human body—your body, to be exact. In that sense, it is not your body anymore, but the human you are possessing. Now, look around. Find where your body is located in your mind's eye. Imagine yourself entering that body, possessing it as yours, and we'll go from there."

"Wait—"

My eyes flew open. "Hasn't everybody already seen me dead? They've definitely entered the classroom by now, what with all the noise inside, so if I just suddenly came back to life—"

Mephisto tsked. "Nein, my little brother. I simply took your body to my office. It's lying on my floor as of currently. The students don't know that you've died yet. Yukio, however, may need this explained to him as well."

He laid a hand on his eyes, tilting his head upward. "Oh, the troubles I go to for family...," the armored demon murmured.

My face burned in anger, but I turned away and did as he explained. Closing my eyes, I took a deep breath and attempted to imagine the school. I was standing next to the fountain, and I looked around, somehow seeing all the humans and their potential. A couple flared brightly, and I assumed they were the exorcists-in-training, apparently still waiting outside the dilapidated classroom. An even brighter flame burned somewhere in the corner of my eye though, and I zoomed in on it, unsure if it was my—no, Okumura Rin's body. Except I was him. Just...somehow, not anymore. Deciding it was worth a try, as there was no other flame brighter than this one, I imagined myself taking over it, taking the body as mine...

I gasped. My eyes sluggishly snapped open, and I could still feel the chill in my bones, in my organs, in my heart...the chill of a dead body.

…

I know some parts are written really awkwardly, and I apologize for that. Someday, I may go back and re-write it, but for now, I mostly want feedback on this idea.

Please review!

~paracuties