Castle Ravenloft

When Castle Ravenloft enters the battlefield,
search your library, graveyard, and hand for a
card named Strahd von Zarovich and put it onto
the battlefield under an opponents control.
Whenever a creature named Strahd von Zarovich
dies, sacrifice Castle Ravenloft. You gain control
of all creatures. For the rest of the game, your opponents play with their hands revealed.