Master of Diversion

Oracle Text

Whenever Master of Diversion attacks, tap target creature defending player controls.

Card Rulings

7/1/2013 The ability will resolve and the creature will become tapped before blocking creatures are declared.
7/1/2013 In multiplayer formats, including Commander, only a creature controlled by the defending player Master of Diversion is attacking can be chosen as the target, even if your other attacking creatures are attacking different players.