Here's what happened (as related to John by Karyn at that moment in the woods):
John had been knocked unconscious and, thanks to John's wish, Karyn couldn't think about think about anything but getting Biff inside her. She begged him to fuck her as she stood, trapped against the chain link fence.
Biff, thinking he had hit the motherload of luck, pulled down his pants and let his (at the time) decently sized cock come to life. Pulling down Karyn's skirt, he entered her and she moaned with delight.
"You like that?" he said before choosing his next unfortunate words, "You like the raw power."
And, listening to what he said and doing exactly that, she did. She loved power. More than anything in the world which, though she was still intensely interested in fucking Biffy, was the most important thing in the world.
"Hey," she said to Biff who was still pushing into her, "Grab that rock."
"What the fuck?" said Biff with a stupid grin, but obliged, lifting the rock, to her face. She couldn't touch it, thanks to her bonds.
"Put it between my tits," she begged.
"You're into some really fucked up shit," said Biff, doing exactly as she asked.
And suddenly she was. Her mind filled with perverted thoughts, exactly at the wrong instant for her to say:
"I wish I was all-powerful."
There was a glow from the stone and it fell to the ground.
"Lady," laughed Biff, "That is one that that I would like to --"
He was interrupted by the sound of fabric snapping. Karyn had effortlessly snapped her bonds, to Biff's astonishment.
"Whoa," he said, "I guess Johnny boy's not so great at tying --"
The look on Karyn's face was incredible. She could do literally do anything she put her mind to, but her mind was nothing but twisted sexual fantasies of Biff.
