Chapter Text
Kageyama pants as sweat drips down his brow.
With intense focus, he pours the last ingredients into the bowl at the center of the pentagram. He slices both his palms, letting blood drip into the bowl before it bubbles and over-flows onto the floor. With wide eyes, he lights a match into the liquid. He watches with bated breath as the sigil catches fire, black masses twisting and contorting into shape before his eyes.
Oikawa had warned him- he told him not to. He said that after last time, he shouldn’t even try to bind another being to him- but Kageyama never got as far as he has by listening to Oikawa. At least if he dies, he won’t be around for the bastard to rub it into his face.
With a final gurgle, the fluid settles into two humanoid shapes as the flames slowly extinguish themselves. Kageyama watches satisfied as the two beings settle into their new forms.
Who ever said you couldn’t summon a demon with sour gummy worms and chocolate milk?
"You've made a mistake human!" The red-haired demon cackles, arching backward to point at the black-haired summoner with long spindly fingers. His ash haired companion looks unamused. Still, he sighs, and humors his partner.
"We will rip apart you pathetic human society as retribution. We’ll destroy everything that your species has worked for- we'll eat your children, rape your women, set fire to your government, and watch as it all falls to ruin. We will take over everything your frail society has created and-"
"Great. Get on with it then."
The two demons look at him in shock, their mouths opening and closing like fish out of water. The ash-haired one recovers first, flexing a set of massive grey wings.
"I'm sorry, I think I heard you wrong I thought you just-"
"I summoned you here to destroy human-kind. Are you going to do it, or do I need to summon another demon?” The black-haired mage scowls.
"I- uh- are you alright man?"
He shrugs, "Not really."
The two demons share a look. They don't really know what to do with that. Humans usually don't just give them the go ahead. A few over the years have tried to bind them, even fewer try to actually kill them. Most summon them, realize they're the real deal and then banish them back to hell. Never have they have had a human that summoned them and then just... let them do what they want? They don't know what to do with that.
"Is this your first time summoning a demon?"
"No."
The red-haired demon blinks, once then twice.
"So, you willingly used gummy bears and milk-"
"They're sour gummy worms and chocolate milk you heathen."
"...Right..."
At this point Semi is just thinking about going back to hell. This is above his paygrade.
"Then is this your first time binding a demon?"
"No."
Semi sighs, Tendo has always been better at interacting with humans than he has, but it seems that even he's thrown off by this vague, blue eyed human. Now that he thinks about it, this one is young. He can't be older than 18, his robes hanging loosely off his body. His skin is pale, and he's thin. Its as if he's stayed inside his entire life. If his words are to be trusted, Semi wouldn't put it past him. Summoning creatures, especially demons as old as himself and Tendo, takes skill and practice. To be able to do so as young as this mage is... its impressive.
"Who were your last summons?"
"I had a contract with Kindaichi and Kunimi." The young mage scowls."They terminated the contract and rebound themselves to Oikawa-san."
The blue-eyed boy's fist clench, magical energy crackling as it rolls off him in waves. Barely contained electricity sparks off his skin, burning Semi as it touches him. To have that much energy stored in a human body is just a terrifying as it is impressive. It’s like this kid is a ticking time bomb- ready to blow at any moment.
Semi wonders if his previous partners knew that. Sure, demons like him and Tendo can handle nutcases like this one, but non-demons, especially young ones try to stay away from cases like these.
People with that much power tend to have strange habits and mannerisms, whether they're human or not(they have to find some way to cope with the power they hold. There's a reason not many people have such massive amounts of power like that.) Semi would know better than anyone. He works closely with Ushijima, a high-level leviathan. He holds massive amounts of power, but he's emotionally stunted. That's not even considering Tendo. Semi can't even begin to figure out what's wrong with him, but he knows that he's more powerful than anyone he knows.
Now that he thinks about it, by that logic there's got to be something wrong with him too. He doesn't think he's particularly powerful- he's a fallen archangel, sure, but other than that... Hm…
"Bond with me, Yamayama-kun!"
Semi blinks once then twice. How much of that conversation did he miss exactly?
"I'll help you get revenge on Oikawa!" Tendo grins, all sharp and predatory. Right. That's what's wrong with Semi. He hangs out with and regularly goes along with this idiot. Willingly.
Still, the newly named Yamayama-kun seems to think about it before he narrows his eyes- clearly suspicious of them(as he should be).
"What's the catch?"
"Catch? What catch, Kageyama-kun~" Tendo plays dumb, but Kageyama doesn't seem to be having it. He grabs Tendo by the neck, and slams him to the floor. Tendo sputters before he grins, grabbing Kageyama by the shoulders to bring him closer. "So, the little wizard's got spunk~"
"There's always a catch. So, what is it? What do you want from me, and what do I get in return?"
Tendo looks at him over Kageyama's shoulder. Semi sighs. He might as well go along with whatever Tendo has planned. He’s never led him astray before.
Kageyama tenses further as Semi plasters himself to his back. He shivers as the fallen angel breathes into his ear.
"What do you think we want from you."
"My soul."
"In exchange for...?" Tendo prompts, bringing his mouth up to Kageyama's neck. The younger boy shivers, his pulse jack-rabbiting against his lips.
Kageyama gasps as Tendo's tongue brushes up against his pulse. "Your services." He manages to spit out with heaving breaths.
"And what if we don't want your soul?" Kageyama freezes as the red-haired demon lays razor sharp teeth against his jugular. Semi is close enough he can almost taste the cold sweat and fear at the back of Kageyama's neck. It’s delicious. At least he and Tendo are on the same page now.
"We want you-" Semi lays his own sharp teeth against Kageyama's skin- not puncturing just with enough pressure that Kageyama can feel the threat, "- in exchange for us. Bound together for eternity."
"Do you want that, Tobio-kun?" Tendo breaths against Kageyama’s skin just as he stops breathing.
"Yes."
"Then say it," Tendo adds enough pressure to make a drop of blood pool- Semi's enhanced senses picking up the scent. "Swear yourself to us."
"But I don't know your names!" Kageyama protests, but Semi chuckles. He’s been around far to long to believe that.
"But you do, don't you?"
Kageyama is silent for a few moments. Semi almost caves, and gives their names but-
"I, Kageyama Tobio, swear myself to the demons Semi, with the human name Eita, and Tendo, with the human name Satori, for all eternity."
The demons smile.
"I, Semi with human name Eita-"
"- and I, Tendo with the human name Satori-"
"Swear ourselves to the human Kageyama Tobio- for all eternity, even after death does us part."
With the strength of an apex predator, Eita and Satori bite down into Tobio's skin, blood bursting across their tongues.
Tobio screams.