Yeah, a little bit. Maybe in-game it would get a little more understandable. In a world, where cards like the Lich King exist, I've tought this one can get a chance too.
your opponent shouldnt do anything during your turn
Yeah, that's a bigger problem for the card. If they would let this ruke break, Hearthstone would be a real-time game. That's why I suggested the following: (Maybe the Battlecry should read: "Your opponent Discover a tragic fate at the start of the next turn". In this way we didn't break the rules of Hearthstone - about opponent activity in own turn.)