Zach had yet to decide what to do when his 12 year old sister Kat came in his room. He saw her and before she could do anything made the door shut and the room sound poof and then changed her into a Cat Girl. She screamed as Her new body parts formed or changed. Cat eats and tail growing as her human ears disappeared and her eyes became stilted like a cat's. Her hands and feet became cat paws but could still do the same things they could do before as her height went from 4'4" to 4 feet. Her clothes changed slightly as they became form fitting as she grew a set of b-cup breasts and her body had a few curves appear on her body as well.
She fell on her paws and knees as she looked at him. Before she could speak mental changes happened making her into a willing slave. "Master what would you like to do nya?" She asked him. He grabbed her and tore off her clothes before he thrusted into her pussy. "NYA!" She moaned in shock as he whispered into her ears. "Have some fun with you." Before he started thrust in and out of her and he nibbled her right one causing her to moan. He played with her breasts biting and sucking both taking turns with each as he fucked her. He flipped her over before pulling her up against his chest as he fucked her going deeper into her cunt. He hit her womb before pulling back and thrusting again entering it. "NNNYYYYAAAA!" Kat screamed as her eyes rolled up and her face was a fucked stupid one. He fucked her for another ten minutes before slamming into her womb one last time and cummed into it.
He pulled out of her pussy and looked that his two slaves who are now sleeping on his bed. He made Emily take over her former self's place and had memories modified for this and made Kat look like she was before the changes he did to her to others but him and his slaves. He thought about what to do as he left his room...