How about simply reporting the Morals President to the teachers. He has no authority to do any of this. As a matter of fact, his actions would require an immediate suspension. Either that of just ignore him until he goes away.
@princeofcups I mean, they already got one teacher involved in all of that, so at least there must be some kind of authorization for it by teachers or something.
That being said, I'm sure those last two tests (the locker and making Mako tempt Shinichi) weren't said to that teacher, and at least the detail of putting Mako to sleep in the first one wasn't clearly conveyed either. All that stuff should be in some way illegal or deserve disciplinary sactions at least.