Well this could end up being darker than I expected. Suppose the question will be how people end up as those 'witches' since it was fairly vague on how that worked. Certainly possible with the gems darkening that the magical girls could be the source making it hilarious that they would need more magical girls to fight against former magical girls to prevent becoming witches themselves
.
Agree a lot of possibilities on how things could play out. If there is a darker side to the magical girl thing (besides fighting for your life) does Mami know? Be twisted if the magical girls do become witches and Mami is recruiting more so she has more potential witches to hunt later. But barely know anything so that's pretty out there speculation.