Sometime around 2008-2010, I read a rather long erotic mind control story, I believe on Literotica.
A young University student was doing a class project with a rich female classmate. During the course of testing her for ESP, he discovered her could access her brain, like a connected external hard drive. He experimented from there, eventually discovering he could make her body change as well as her mind. She becomes his devoted girlfriend, buys him a car and furniture for his apartment. Her mother eventually gets involved, and he has to control her. He discovers that the mother had been secretly seeing the dean of his University, and begins to control her as well. It had several parts, culminating in the college Dean going rogue and the main character having to copy his brain into her body to stop her plans.
It wasn’t any of the Master PC stories. I don’t think so, anyway. It certainly never used the phrase ‘Master PC’, but he was using a computer to edit people.
A few other details I can remember: