The Weird Sisters

{t}{b}When three sisters enters the battlefield, you may discard or sacrifice Legendary creature named Duncan, king of Scotland. If you sacrifice and discard A card in this way, you win the game.
"All hail Macbeth, Hail to thee, Thane of Glamis! All hail Macbeth! Hail to thee, thane of Cawdor! All hail macbeth, that shalt be king hereafter!"