Demon Cells

The demons are in a very similar situation as the werewolves. However they're a special case. They must be kept in their human forms or else they could escape, so they've been fitted with special collars and anklets which were specially made to suppress their powers. They are unable to use any of their powers, and are helpless as long as no one unlocks their collars and anklets. Test subjects are allowed to come gawk and them, but demons rarely ever feel like chatting with mortals. However they do happen to show some interest for the D group.