Change all face-up monsters on the field to face-down Defense Position. During the End Phase, flip all face-down Defense Position monsters your opponent controls face-up, and your opponent draws 1 card for each.
Personally I think this card is a great card to side deck next format.
Pros:
Stops OTKs
Can be used on your turn in conjunction with Red Dragon Archfiend
Stops plays
One of the few the few ways to stop Key Beetle with Safe Zone
Not affected by Mind Drain like other OTK stopping cards (Scarecrow, Battle Fader)
Can not be hit by Royal Decree like Threatening Roar
Good at stopping your opponent from attacking, Synchro and XYZ summoning and stopping Ignition effects.
Saves your monsters from Mirror Force
Cons:
They draw for each monster you flipped (This can be a pro in some cases where your opponent has 5 cards in hand and 3+ monsters on the field, causing them to discard, but a majority of the time this is a con)