In another world, Urd would have explained away the odd effects of Peorth's alterations as a goof, why messing with Urd's potions isn't a game for amateurs, and that her potions aren't so poorly made that they'd screw up a perfect match.
But brewing the same thing time and time again doesn't aways make the same thing. Maybe the temperature was off, maybe an ingredient wasn't as fresh, or maybe Peorth's alteration magic had some extra signs involved.
Whatever it may be the cause, the end result was that any woman's eyes that Keiichi gazed into would want to dominate him and would have a desire to use her bottom to do so. Not only that, but Keiichi would be enslaved to a woman if she used her behind on him.
'Megumi, please stop this! Megumi! Mistress Megumi, get your sexy ass... wait, Mistresss-AH!' Keiichi thought right before Megumi's toes made him cum.
Megumi covered her mouth with the back of her hand and chuckled, "Heh heh heh. I bet that was just like one of your hentais, even down to the incest part."
She stood up and began to wipe the semen off her feet onto the grass. Once her feet were cleaned, Megumi looked down at Keiichi, who was still laying on the ground. She asked, "Well, Keiichi. What do you have to say?"
Keiichi was taking deep breaths of fresh air. Once he was able to speak, he looked up at Megumi, who still had her ass facing him. From what he could tell, she had a lust, but cruel, expression on her face. He wanted to tell her off or ask what gotten into her.
But his mouth said, "Whatever your orders are, I'll follow them, Mistress Megumi."
"And why is that?" Megumi asked, her mouth getting curls of a smirk.
"Your butt, Mistress Megumi," Keiichi uttered.
"Heh. Pervert Bro. Your face did feel really comfortable to sit on. Maybe I'll get a few of my friends to try you?" Megumi said as she walked away to put on her shoes. "So... are the pictures ready?"
"Y-yes, but they're back at the temple," Keiichi answered, slowly getting up.
"I'll see you there," Megumi said, briefly bending over to use her butt to smack into Keiichi's face.
Once Megumi left on her bike, Keiichi shivered. He had to get help from either Urd or Belldandy, but without them deciding to enslave him.