Mirror Battle (Encounter idea)
Here's one for you DM's that want to fight your players, with your players (or at least DM controlled players) The players are going through a dungeon, when they come across a strange mirror. The mirror is on the side wall of a room that they need to get through. The door on the other side of the room will remained locked till all players enter the room (if your players don't do this & can't figure out how to open the door, give off a hint that has something important looking, correspond to the amount of players). Once all the players enter the room, the door that everyone entered will lock, & the mirror will start to glow a misty purple. Soon enough, a gooey purple substance will come out of the mirror & form itself into a copy of each player. The gooey copies will then proceed to fight the party. If the players win the fight, the mirror will shatter & the doors to & out of the room, will open.