NOTE: Seeing as several people already threw the "No TG" rule out of the window, I don't see any harm in doing it myself.
Rouge picked up her her cell phone, and dialled the young fox's number. After a few tense seconds, she heard his voice at the other end.
"Rouge? What's up?" He asked, sounding excited to talk to someone.
"My, aren't you a little hyperactive today." She teased.
"Sorry, I was just really, really bored. Ignore what botanists tell you. Plants do not make good company." He explained.
"Right." Rouge giggled. "So, I found this weird ring, and I was wondering if you could take a look at it. Are you in Knothole?"
"Sorry again, but I'm at my Mystic Ruins lab." Tails apologised.
"That's even better. I'm at the GUN building in Station Square. I'll get a train. See you there!" She said, hanging up. "Well, the trap is set, now I've just got to spring it."
***
Rouge arrived at the Mystic Ruins station and instantly soared into the air, looking for Tails' workshop. She quickly found it on a hill nearby. It was easily recognisable, as it had a launch ramp several hundred meters long to the front, on which was parked a red biplane. She walked up to the door, and knocked on it. Tails opened it a few seconds later, and welcomed her to his home-away-from-home.
"Sorry about the mess Rouge. Now, what was it that you wanted to show me?" He asked, curious. Rouge's sweet smile turned to a sinister grin, and she fired a beam of light from the ring at Tails' eyes.
"Why, my new hypnosis ring of course." She smirked, as Tails eyes glazed over and he slumped forward, somehow still on his feet. Rouge put her finer beneath his chin, and lifted his head up to meet her examining stare. "Are you ready to hear your new orders, Tails?"
"...Yes... Rouge..." Tails droned.
"Good boy." Rouge said, complimenting her pet. She led him over to a couch, cleared the robot parts off of it, then sat down, allowing Tails to perch on her lap. "Now, first things first. No more pointless experiments. No more doing things with 'science' as your only reason. From now on, you only do experiments when I tell you to. And your inventions must all benefit my career as a jewel thief. Understand?"
"...Yes... Rouge..." The fox repeated.
"Excellent. Now, speaking of my career as a jewel thief, you will be joining me."
"... As you wish...... Rouge..." Tails said, accepting his new career.
"Buuut, not as yourself. You see, you're too recognisable. So I'm going to give you a makeover." Rouge said, leading her victim further into his trance.
"A... makeover?" Tails asked.
"Yes, Tails. You see, I know a lot about you. I know how you've always longed to be like me." Rouge lied, manipulating Tails' thoughts and emotions
"...Really..?" He asked again, confused.
"Yes my dear. You've always wanted to be a lovely, sexy female jewel thief." Rouge smirked, watching the fox's mind change in her hands.
"...I...have...?" Tails said, further questioning these orders.
"Of course, sweetie. Would I lie to you?" Rouge asked, countering Tails' question with one of her own.
"..."
"Would your mistress lie to you, Tails?" Rouge pressed for an answer.
"No... Mistress..." Tails replied, a vapid smile breaking out on his face...
Now, does Rouge have Tails build a gender bender machine, or have him become a cross-dresser?