FYI, the anime watchers wouldn't know this, but in the manga Satan didn't only use Shiro's blood to summon the Gehenna Gate, but a strange indecipherable incantation too. So basically, it's a Summoning, and like father like son :D

Yeah, had this crazy idea one night, just had to write it down as I was on a writer roll today.

Enjoy!

Disclaimer: I don't own Ao no Exorcist/Blue Exorcist.

Title: Why Rin shouldn't Summon
Genre: Humor/Drama
Pairings: None
Rating: K+
Warnings: Uhh, mentions of blood? Nothing else really.
Words: 1139

True Cross Academy cram school

Subject: Art of Sealing

"Umm, Sensei, are you sure it's alright for you to teach this class?" Rin heard Konekomaru ask uncertainly.

Their sensei, the one who taught Physical Training (Rin couldn't remember his name, only that he had a 'kitten' that often called him) had been called today as a replacement for Neugauz-sensei in the Art of Sealing. He was sure the rest of the students shared his opinion of wondering if it was safe to be taught by him how to summon.

"Yeah, we already went through this with Neugauz-sensei. We've got two tamers in the class, isn't that enough?" Bon asked.

Neko-sensei (because that is what Rin was going to call him from now on) just waved him off with little concern. "Neugauz-sensei's got a cold and couldn't attend, and somehow he lost his papers so I can't help but start from the beginning. Also, I heard that not all of you really tried so we're going to rectify that."

"Still," Bon insisted. "We shouldn't do this without an expert in the subject…"

Neko-sensei shrugged. "I was told to repeat the class and I will. And it's not like anything could really happen. Neugauz-sensei already gave me a few slips of paper with a magical circle drawn on it; all you have to do is smear some blood on it and try. And if it goes wrong, just tear the circle and we're over with it. Now, come stand in a circle on the front and grab a paper."

He was right in a way, Rin thought as he stood up. All it would take to prevent a disaster was to tear your magical circle and BAM, no danger. He shrugged, feeling like it was worth a try, even though he knew he surely had no talent.

They all grabbed a paper, some two, and went to work. Izumo swiftly summoned her two white demon foxes, and Shiemi consulted with Nii-chan first before tearing his paper and summoning him again with a few mumbled words.

Neko-sensei nodded at the two girls in approval, then turned to the rest with raised eyebrows. "Well?"

Konekomaru shifted under the penetrating gaze. "Well, the three of us aren't that good at it-"

"Unacceptable! I said all of you are going to try. No exceptions! Say whatever first comes to your mind, like Moriyama-san did. I won't let you out of this class until you try."

Grumbling the three boys got down to work under the watchful eyes of their sensei. Out of the corner of his eyes, Rin saw the two remaining members of their class stare at their slips of paper, mumble something under their breath (although the kid with the bunny didn't move his lips) and then throw it away nonchalantly. They didn't even draw their blood.

He studied his own paper for a moment, not understanding the complicated patterns at all. He tried to think of some words to say, but nothing came to mind. He furrowed his eyebrows, bringing a hand under his chin in a thinking pose.

Maybe he'll know if he adds the blood first? He bit his thumb, his sharp teeth sinking into the flesh deeper than he had intended, and smeared it across the paper. He knew sensei had said only a few droplets were enough, but still, the more the better, right?

He glanced at Shiemi, who was acting overjoyed at Nii-chan's return. Whatever comes to his mind first, huh? Still, an epiphany eluded him.

Yet the more he stared at the paper and the blood covering it grotesquely, the more he felt a a sort of morbidity at it all. Hah, what were they doing here, using rituals involving blood to summon demons to do their bidding. It seemed kind of dark all of a sudden.

Faint words came to his mind as he started to view this exorcist practice from another perspective entirely, and no matter how much Rin would try to decipher them, they escaped him as soon as they appeared. It sounded familiar somehow, like he'd heard it once before…

Neko-sensei was still busy grilling Bon to try say something for a summons when Rin unconsciously began reciting the sounds and non-words running through his mind. They were spoken in an almost whisper, barely audible, yet at the other end of the formed circle the guy with the hoodie suddenly jerked his head up in his direction. Rin paid him no mind, still staring at the paper in unbroken fascination.

When there were finally no more words to be said and Rin himself was surprised he'd even spoken without realizing it, the mood in the classroom abruptly shifted. Where before it had been filled with bemusement and irritation at their persistent teacher, not it was replaced with a heavy feeling that pressed down on all their hearts. All conversation ceased and dead silence engulfed them.

At Rin's feet, starting from the few drops of his blood that had fallen down without his notice, a black expanse appeared out of nowhere. It started spreading outwards as the others, Rin included, sprang back in shock, and continued evolving into a rectangular shape.

Everyone stood agape of the something that clearly wasn't supposed to happen, and only Rin realized in clear horror just what he might have summoned. Oh God, please not that, how could he even do that? Wasn't he told that night that only one being in existence could summon it? What the hell was going on?

With ever-rising terror he waited for the Gehenna Gate to fully form, for all those small creatures to rear their heads out of the abyss, for the many eyes and malformed bodies to grace their sights…

But in the next moment, it was gone.

It took a moment for everyone to grasp there was no danger, no heavy pressure anymore. The class collectively blinked once, twice, before they fell to their knees breathing heavily. Shima skipped that part and fainted on the spot. Shiemi started inexplicably crying and Bon cursed up a storm trying to grasp what just happened. The boy with the bunny had sat instead of falling to the floor, choosing to stay silent. The rest of the class was just busy trying not to hyperventilate.

The only ones left standing were a shaky teacher that vowed to never replace a class not his own again, a stupefied Rin, and the boy in the hoodie. Almost in slow-motion, Rin's head turned to the side, unable to grasp how the other could have moved to his side under all that pressure. Then the guy slowly reached for his hand, lifted it and placed two parts of a torn paper in them.

"Never do that again."

Rin could only nod his agreement.