To be honest... probably nothing. I don't know anything for certain, but maybe I'd consider it like this -- they can only summon one a week, and if we aren't vigilant, the amount of people acting up will also only increase over time.

They did also suggest to me that it's not impossible for the monsters to attempt to kill one another, or even their own matching affliction in the name of "competition", but worst case scenario...

[ Just a whooole lot of monsters if they don't stay sharp or they refuse to participate in the Saturdays. ]