She agrees to be corrupted

It should have been a difficult decision. But it wasn't. The opportunity that Elizabeth had been waiting for her entire life, the promise of power and lust that you embodied, was not something she would squander.

"Yes! Yes, of course! Change me now!", she begged, still ramming her vibrator through her pussy.

"So eager", you chuckled as you sauntered towards the bed and climbed on top of her, face to face, sandwiching your stiffening cock between your two bodies. Your heavy breasts pushed against her bare chest as your black lips met hers, with her tongue intruding into your mouth before you could even react. "So, so eager", you said telepathically while the two of you passionately made out.

The librarian's hands were all over your body, and soon enough she began to get more confident in her situation, shamelessly groping your ass and even smacking it playfully. She didn't know where this was all coming from, the woman had never even kissed a girl before, but it was as if she intuitively knew what to do. Your hardened cock now started to leak black precum between your bodies, which slowly began to be absorbed by the brunette's pale body, beginning her corruption.

"You know what you need to do, Liz. Unleash your true self", you communicated to her mentally. There was no hesitation. With surprising strength she pushed you around, and she climbed on top of you, her upper body standing upwards as did your erect cock right in front of her. The look on her face showed a wicked, hungry smile, far removed from the usual timidity.

"I do", she said, not a trace of her stutter in her voice. She impaled herself on your penis, yelping loudly as she lost her virginity in one swift move. She didn't stop, however, and began to wildly ride your shaft, losing herself in the pleasure. You pushed your hips along and grabbed her bony ass, driving your cock as deep into her as it was humanely possible.

Your precum was already showing it's first signs of success as her veins began to be covered in black, transmitting the corruption throughout her body from her pussy. At the moment it seemed to be avoiding her clit, however.

But not the rest.

"It's happening!", she yelled in joy as the nubs that were her breasts began to develop into a full, firm pair of tits. They began to bounce along with her all the while you felt her butt taking shape into a beautiful piece of ass and her lanky body took a hourglass shape. The corruption reached her face last, with soft crunches being heard as her face reformed to take a more angular and stern looking shape. The face of a true succubus domme.

She discarded her glasses away as her eyes turned completely black with feline, menacing yellow irises in place. "More!", the woman demanded and began to ride you harder, faster, as her muscles turned stronger yet still femenine. You felt yourself close to cumming, but you needed to see one change in her before realising your load.

She threw her head backwards with a long moan as her clit began to pulse invitingly, but still at the same size as before. "Do you want it, Liz? What would you do with it?", you asked calmly, already aware of the answer.

"Yes! I want it! I want to fuck all those prude, annoying bitches! I'll turn them into my sexy demon slaves!", she proclaimed, with more certainty in her voice than had ever been before.

"Good answer", you replied and watched as her clit finally began to lengthen, inch by inch, taking the form of a human penis in no time. She stroked it rapidly, moaning incessantly as it grew harder and longer than most males could ever hope for, a full eleven inches. Below, a pair of heavy balls had dropped just above her pussy.

You couldn't hold it any longer. The sight of your former neighbor growing into such a oversexed form turned you on so much that began to pour wave after wave of your corrupting cum inside her, at the same time her new cock also released its dark load atop of you, which you rapidly began drinking. It was absolutely, sinfully delicious.

"Fuck yes!!!", she screamed from the bottom of her lungs as her body finished her transformation into a sincubus, with her horns and tail appearing on her and her skin turning into a pale shade of purple.

Two minutes later, her last drops spluttered out of her still erect cock while she climbed out of you with a nice *pop*, her pussy leaking your own dark cum.

You saw no trace of the shy and introverted librarian in front of you. In it's stead, a stunningly sexy Sincubus was exploring her luscious curves and tasting her own cum with her long tongue.

"Mmmm", she spoke telepathically, having acquired the same extent of your powers, "that was amazing, Sister". Even her telepathic voice was seductive, dripping sensuality with each syllable. "I do wish I could stay and fuck your ass until you beg me to stop but...", there was a fire in her eyes as she said the next words, "I have a library full of irritating whores that need a new Mistress"