Ty decided he'd rather not do anything to interfere with Eileen that she didn't agree to, even if it was tempting. Thankfully, he soon realised something he'd like to try using his powers for that he could do on his own. He remembered how weird and nice it had felt when he'd turned into a girl, and he realised he wanted to try being his girl self again.
Hastily he undressed, pulling off his T-shirt, dropping his shorts and tugging off his boxers, casting them to the floor in a neat pile. He stood naked and stared at himself in the mirror for a moment, anticipation racing through him, and soon focused on the wish just as he had earlier that day.
He breathed heavily as he felt his body fill with transformative hormones and his sex start to reassign. The changes felt more natural to him having changed before, like following a path to a familiar place. His figure shifted inwards all over, his height declining and his muscles receding to be more lithe and petite. His hips flared outwards and his butt expanded. His face resculpted subtly, making him look like the same boy yet distinctly not him, a fact affirmed by his voice increasing in pitch as the bulge of his larynx vanished from his neck. Even his skin was altering, as it turned softer, smoother, more supple to the touch.
By now only two parts of him had not changed- his flat boyish chest and hard penis. His arousal only intensified as he saw these too transforming. His nipples swelled and grew sensitive, and flesh started to expand under them, his chest filling out until he had soft B-cups. His erection rapidly receded into him, still seeming to throb with arousal just as much as it shrank, and the sac between his legs sank into his crotch. When the testicles pulled up from inside it and started to rearrange into ovaries, something clicked in Ty's mind. Emasculation and feminization. He turned to she. And as his penis finished receding into a clitoris and his scrotum opened out into her vaginal lips, it felt like she had turned into the person she always should've been.
After a little while, Ty was able to focus on her reflection, and was really pleased with how she looked and felt. The sex she had was hers to control, and she loved what she'd used that control to make herself. Her head was full of ideas about what to do with herself now, and she wondered which to choose...