She forfeits

Joy couldn't bring herself to sacrifice Jasmine's mind to protect herself, so the choice was obvious. She picked up the book that had been tossed towards her, and read over the spell, and then cast it. She'd been practicing with some simple spells the last few days, and this one wasn't that much more complicated, so it was cast within moments. And then Joy felt...empty.

"I need DNA from my new owner..." Joy mumbled, monotone as she spoke. William pulled out of Jasmine's ass and held his cock in front of Joy's face, and stroked it. She got the idea, opening her mouth wide for him, and then he came, some cum landing in her mouth while more landed on her face. But once she swallowed his cum, her fate was sealed.

She felt less empty. But she certainly wasn't herself anymore.

"How may I serve you, Master?" she asked with a smile, as she looked up at William. She knew who he was now. Who she was to him. She was his pet witch, and nothing more than that...serving him was her entire purpose in life.

"Damn, she's so hot like that..." Jasmine mumbled, before William looked at her, "You can let your old personality take back over. I don't need your planning anymore."

Then Jasmine's eyes widened, and she swallowed, "I'm so sorry, Joy..."

"Don't be sorry," Joy mumbled back, "This is my purpose..."

"Use your magic to make me hard again, and then bend over, bitch," William said, and Joy wrapped her hand around his cock, using a simple spell to instantly get him hard, before she turned to face away from him and bend over, face down and ass up.

Her new Master dropped to his knees behind her, and let out a groan as he sank his cock into her ass, with her moaning out as she was taken by him, "Mmm...to think, all this started because I wanted to teach a nerd her place...and now I have a pet witch. Nobody can stop me now...every woman in the city is going to be my eager little cockslut..."