It is simple, you make a wish and the following user grants it but makes it have a twist. They in turn also must make a wish example:
USER 1: I wish to have all knowing wisdom!
USER 2: Wish granted but your head grows too large that your appearance looks freakish and no one wants anything to do with you. I wish to have super powers
get the point? Good now then the first wish:
I wish all the children who were homeless were homeless no more and lived safely.