Slave of Bolas | Magic: The Gathering
Formats Slave of Bolas is Legal in
Official Oracle Text for Slave of Bolas
Official Rulings for Slave of Bolas
5/1/2009 : If you don't control the targeted creature when the "at end of turn" ability resolves, it won't be sacrificed. If it's still on the battlefield but under another player's control, the ability won't try to have you sacrifice it again at the end of the turn after that.