Note: All characters in the following story are 18 years of age or older. This is an edited and completed version of a Chyoa story thread I wrote on "The Devil's Mystery Box" started by bbcummings.
Professor Ethan Bell shook his head sadly and closed the box with a finality he had never expected to feel. It was as if something had left him, as if the overwhelming drive and purpose which had filled him ever since the moment ever since he had lifted the blade and seen the parchment beneath it had suddenly left the 46 year old Professor. Years spent learning the ancient language and deciphering the cryptic ritual the ancient document described. Procuring all the exotic materials and locating and purchasing a home for his family on a convergence of ley lines. Everything had been perfect. He knew his chanting of the incantation had been meticulous and the knife had plunged into the solid concrete floor to the hilt at the apex, the air had strummed with ozone and untold power.
Then... nothing. The great spirit of power and wisdom had not appeared. Dispiritedly Professor Bell finished cleaning up the remains of the ritual and looked at his watch, shaking his head as he realized it was long past time to go to bed. Looking back he spotted the blade still in the floor and took a step towards it before a sudden wave of confusion filled him and he turned and wearily climbed the stairs, forgetting all about it. As the lights switched off and the basement door shut the jewels on the cursed blade's hilt glowed faintly in the darkness.
***
Hours earlier -
In a bedroom two stories above, where the true convergence of ley lines met, reality cracked and a fiery portal opened. Slowly a massive muscular form emerged, the hole in reality shutting behind it. Inhuman eyes saw impossibly well in the darkened bedroom and bestial nostrils flared as they caught the enticing scent of fresh young female flesh from the bed. A clawed hand reached out and slowly pulled the sheet back, a low growl escaping him as the diminutive form beneath was revealed.
Katie was nineteen and enjoying her senior year while looking forward to a bright future. Known as a happy and kind blond girl with her cheerleader's physique and girl next door looks combined with a ton of natural energy she threw at every task.
Right now the teenager was enjoying a regular dream which she knew was pathetically stereotypical but still one she enjoyed. In this dream it was the night of prom and after the dance she was giving her virginity to her real life boyfriend Brad. Everything she had imagined sex was like was blown away by this dream, far more vivid than any previous one. Brad had a confidence and skill that
"I love you Brad!" she whimpered as his length filled her again and again.
"Katie you are mine." his gaze burned through her, his familiar features filled with an intense feral hunger she had never seen on Brad's kind young face.
"Yes!"
"You will always be mine." He thrust again, drawing another cry of ecstasy from his quivering lover, "Forever."
"Oh yes Brad, that's what I want too!" she moaned as new waves of pleasure shook her body and mind.
"You will be my little whore forever." He smiled as Katie went suddenly stiff beneath him as she looked up her loving boyfriend's face to it transformed into a mask of red eyes with demonic slit pupils. "I can't wait to devour your soul."
Katie opened her eyes in her own bed but the nightmare wasn't over. A 400 pound beast was on top of her, *inside of her*. The worst part was how utterly good it felt.
"So glad to see you awake. Wouldn't want you to miss your first time." The monster growled mockingly as he thrust deeply into the defenseless girl.
Katie opened her mouth and screamed but her cries were swallowed by the old house, failing to reach her father below. Katie thrashed helplessly, her body in the thrall of supernatural arousal while her mind reeled in shock.
"No one can hear you. Besides," he chuckled, "I thought you were mine."
"I don't want this. Why does it feel so good!" the blond sobbed.
"You will never have another lover like me, just give in to the pleasure."
"Oh god!" Katie wailed, "Please save me."
"He can't hear you, little lamb. Embrace the pleasure I offer. Just surrender to me, succumb to your lust and you may enjoy this, free forever from shame and doubt." He hissed. "No human man can make you feel this way. Yield!" He roared, deliberately forcing the girl to feel every veined inch as he concentrated his influence on her mind, drawing out feelings of lust and perversion and fanning them ever higher...
"This can't be happening." her futile struggles were slowly becoming something more rhythmic as the demon's monstrous thrusts sent electric waves of pleasure through the deflowered virgin, making it increasingly difficult for Katie to concentrate and allowing his dark influence to creep deeper into her being.
"You know the truth, this feels good." Asmodeus bent and ran his slavering tongue over her heaving breasts and up the teenager's slender neck, making her shudder in mixed fear and disgusting pleasure. "I can taste the sin in your soul. How long can you deny me?"
Katie squeezed her eyes shut and shook her head in useless denial as her cheeks burned with shame. Even now she couldn't cease the slow rocking of her hips as she helplessly slid up and down the shaft impaling her.
Asmodeus drank in her shame and humiliation, feeling his influence grow as sin entrenched itself deeper into his victim's mind, pouring exquisite pleasure until it was becoming difficult to focus on anything but the overwhelming pleasure which shot through her traitorous body with each ruthless thrust. It had been far too long since the demon lord had enjoyed the charms of a human woman, and even longer since he had a fresh virgin impaled on his cock. It filled him with an entirely alien sense of pleasure as he felt her will faltering, allowing his aura to overwhelm her own and his supernatural senses feel her traitorous body beginning to prepare to breed.
Her pussy began to secrete silky fluids and her cervix blossomed open and soon he was fucking her little womb, the petite blond cheerleader's normally flat and fit tummy bulging outward as her organs shifted with every ruthless thrust. Katie's scent shifted as hormones in his tainted pre-cum forced ovulation and she became hyper-fertile, her ovaries throbbing as they pumped thousands to eggs into her clenching uterus, where they prepared to receive his imminent load. Even the demon's self control was tested, before inseminating the girl he first needed her most precious possession.
Amongst his victim's desperate panting and hopeless moans came what Asmodeus had been waiting for when a faint whisper escaped her lips, "harder..."