DeMorrell was no idiot; he had already wished up protections for himself when all he had was the staff. But his precautions were incomplete. For instance, he hadn't asked to be immune to wishes; instead, he just made sure the staff worked only for himself.
He ran through the ideas in his head. Immunity to wishes... no, maybe he needed to get more specific. He could be immune just by wishing for something, since wishes can't be changed. So he'd have to wish to be whatever age he wanted, be male, wish for eternal life, then wish that the wishing girl would always teleport to him when he wanted a wish, then wish that the stone would teleport around the world so that everyone thinks he's a rich guy, etc.
"I wish I was 22 years old."
That would have worked to keep any wishes from changing his age in the future, but he messed up. Or rather, Wendi messed him up.
Where DeMorrell stood were twin 11 year old girls. Together, they are, after all, 22 years old.
And the side effects were worse. Reality changed just as if DeMorrell had always been two 11 year old girls. Previous wishes couldn't be reversed, so DeMorrell still had an office and a building complex--only it was now a toy office and a set of toy buildings, since it would make little sense for 11 year old girls to own real buildings. Suddenly the sun was shining again, as the whole place became a few pieces of plastic in the sand in front of the two girls. Most of the inhabitants who DeMorrell had wished up had become dolls; the few real people working in the offices wandered off, since they no longer even remembered any buildings there.
The handcuffs, which DeMorrell had bought rather than wished up, simply vanished, since 11 year old girls wouldn't have them.
There was a lonely shack in the desert that was the transformation machine, just a few feet away where it always was, and useless since it still worked by the old DeMorrell's voice.
"I think your parents are calling you," said Wendi, and kicked the girl with the hand on her breast, grabbed the staff from her, then ran. Wendi wouldn't be surprised if some of the former office workers were now DeMorrell's parents, but she wasn't planning on staying around to look.
"Follow her!" yelled both of the girls to Jon and Karyn.
"You're not my master," they said. Unfortunately, they had heard the wish, so in their reality they still thought they had to obey the original DeMorrell.
Meanwhile Wendi was running like crazy. All she had to do was find someone outside the wish range and get them to make a wish, to save Jon and Karyn. Of course, the edge of the range was still very far away, and stone wishes had a bigger range than staff wishes anyway. If she could make it to the nearest city....