Forum:Monarch effects

I got a question with Mobious the Frost Monarch. Lets say I got 3 cards face down magic cylinder, mirror force and trap hole. When my opponent summons mobious I use trap hole, but since it was summoned he gets to destry 2 of my trap cards. My question is does he choose the 2 cards before I activate trap hole? Or do I trap hole then he chooses 2 cards? Another question is if my opponent summons a zaborg and I use compulsary unit on my own monther to return it to me hand does he kill himself? or it is simply a mistarget?