Dark World Brainwashing (COTD-EN074) [Code of the Duelist]

When an opponent's monster activates its effect, if you have 3 or more cards in your hand (except during the Damage Step): You can target 1 "Dark World" monster on the field; return it to the hand, and if you do, the activated effect becomes "Discard 1 random card from your opponent's hand".