Sitting alone in his small apartment, memories of his whole life adorning the walls and books scattered on the floor, Izuku wondered how his life came to this. Just a few months ago, his life was perfect. He had just graduated college, it was coming up to his 5-year anniversary with his gorgeous girlfriend Ochako, and they were finally moving in together. Sure it was mundane, but some of his happiest moments were late nights researching the best types of light fixtures while Ochako tries to pull him to bed. It's those small things in life he took for granted that he was missing the most right now.
Soon after they moved in together, Ochako started getting sick. Really sick. As the days went by she smiled less, laughed less. She couldn't dance and move the way she used to. Her body grew weaker and weaker until they had no choice but to put her in the hospital. Doctors ran test after test, but they couldn't figure out what was wrong, and as they were she just kept getting sicker. Izuku visited every day, trying to keep her spirits up but soon she stopped giving her sweet smiles at all.
When he wasn't at the hospital he was researching. He devoured every book he could find that could possibly have a cure, from medical journals to ancient remedies, he barely slept looking through them all. But no matter what he read nothing had the answers he was desperate for. So he turned to more and more obscure options. Nothing was to out there if it could save her.
And that's how he got here. Demonology tomes and textbooks spread across the floor, all the furniture in the living room pushed to the walls to make room for the circle he drew. Carefully, he double checked every symbol and rechecked his books, even though he had already committed it all to memory. Breathing in, he lit his candles steeled himself.
"Denizens of the underworld, hear my call. With my blood I call you, and bind you do my bidding!"
He slashed through his palm with a quick flick of his knife. Drops of blood beaded on the surface, before dripping down his fingers and onto the floor. As the first drop touched the circle, a deep red glow snaked its way from the point the blood hit down the runic lines till it collected in the centre. The glowing light grew until it was almost blinding to look at, and he had to squeeze his eyes shut.
As the light started to fade Izuku went to take his bloody hand from its place above the ritual circle, but a hand clamped around his wrist. Startled, his eyes flew open to meet a crimson gaze. Spiky golden hair surrounded curled horns, and a tight crop top revealed his toned skin. Large wings extended behind him, littered with holes seemingly caused by tiny burns.
"Where d'ya think you're going, huh?"
The man smirked, pulling Izuku closer by the wrist. He brought the hand to his mouth, and Izuku caught a hint of fangs as his tongue snaked out to lick the wound.
"Wh-wh-what do you think you're doing?" Izuku screeched as he attempted to pull his hand away. But the grip on his wrist stayed firm despite his struggling.
"Jesus dumbass, settle down. I'm just taking what's mine."
Despite his words, the demon seemed to be taking great pleasure in languidly running his tongue up Izuku's palm, getting every last possible taste of his blood. After what felt like entirely too long, the vice grip on his wrist was released and Izuku took the opportunity snatch his hand back and retreat a few steps.
"So shortstack, doesn't quite look like you're in much trouble. What is it then? Any assassins I can blow up? Civil wars I can start? Don't hold out on me, what's got you desperate enough to summon a demon?"
"I-it's nothing like that! I… Well I was wondering if you could- if you had the ability to heal someone..."
The demon's shoulders slumped. "That's all? Fucking boring, I could do that in my sleep. As long as they're not dead it's not even a sweat, so what's the issue Greeny? You look healthy enough to me."
"No, you've got it wrong! It's not for me. I, I have a girlfriend and she's really sick, can you help her?" Tears pricked at Izuku's eyes.
Crimson eyes bore into him, unimpressed. "Haaah? You mean to tell me you summoned ME to deal with your petty fucking romcom wish? Jeez you're pathetic."
"Well who was I supposed to call? Ancient texts don't exactly give me much detail! Tell me what I did wrong and I'll find someone better okay?"
The man glared at him and growled, "Back the fuck up shorty. You called me here and I'm gonna fucking do it alright? There's nothing I can't do so don't doubt me you got that?" He walked over to the circle and crouched at the runes surrounding it "Don't know how you didn't mean to summon me, you've got my fucking name right here."
"Uh, well, I can't- I mean, I don't know how to read them. Um, but what is your name?"
"You dumb fuck, how did you expect to do the binding ritual without my name? But since I'm such a nice guy, I'll give it to you. The names Katsuki, Demon of Victory." He examined some other runes on the circle. "And your name is… Deku? Jeez, your writing is chickenshit."
"Um no, my names Izuku. Midoriya Izuku. It's very nice to meet you!" He hastily bowed, remembering his manners.
"Whatever, its fucking Deku now. So, you gonna bind me or what? That bloods not gonna keep me tied here forever y'know. Or are you too inept to do that?" Katsuki smirked, looking entirely unconcerned.
"N-no, just give me a minute!" Izuku rushed back to his notes and tomes to glance through them once more, and took a deep breath to steel himself.
"Demon of Victory, Katsuki, I call you with my blood and offer you my soul and servitude. In return, I demand you grant victory to Uraraka Ochako in her battle against illness. If you accept, take of me what you will and grant your power!" Izuku's voice seemed to echo around the room, and Katsuki's eyes darkened to a deep black.
"I accept." It came out as unearthly growl as power sparked in the air, causing tiny explosions. He grabbed Izuku's outstretched hand, and fangs sunk into the pulse of his wrist.
Izuku braced himself for pain, but there was nothing, not even a slight discomfort. Only black, black eyes that he seemed loose himself in. Blond eyebrows quirked in amusement as he looked on, transfixed. Red lips pressed against his wrist stirred something in him he wasn't ready to acknowledge. When Katsuki finally pulled away, a pink tongue snaked out to lick those sinful lips, fashioned into an all too smug smirk.
"Well Deku, are you ready to win?"