The intruder picked up the box and opened it, they unfolded the note and after skimming it crumpled it up and threw it over their shoulder.
"The fool" the intruder said "entrusting this to a mere child"
After closing the lid and taking the stone the intruder put a very simmer looking one in a very simmer box in it's place. Both the box and stone it housed where rounder.
"This will work as a good test, well entertainment at-least" The intruder said before vanishing.
The stone that Jon now owned worked very much like the stone his grandfather left him, but with one big difference. Instead of the wisher and all within earshot remembering the way reality is supposed to be, random people equal to the wisher and those within earshot in number would remember instead.
So if Jon wished that Sara was a guy with Karyn in earshot, Sara would be a guy but Jon and Karyn would most likely remember Sara being a guy, but Zoe and Steve Farber would remember him as a her.
There is a slight chance for Jon or Karyn to remember, it's random.