Siempre que una o más criaturas que controlas hagan daño de combate a un jugador, puedes sacrificar una de ellas. Si lo haces, muestra cartas de la parte superior de tu biblioteca hasta que muestres una carta de criatura que comparta un tipo de criatura con la criatura sacrificada. Pon esa carta en el campo de batalla y el resto en el fondo de tu biblioteca en un orden aleatorio.
If you don't reveal a creature card that shares a creature type with the creature you sacrificed, you'll just reveal and randomize your library.
Compare the revealed cards to the creature as it last existed before it was sacrificed, not to the creature card as it exists in its owner's graveyard, to determine which card from your library you put onto the battlefield.
If the sacrificed creature has no creature type, no card can share a creature type with it.
You'll reveal cards until you find one that shares at least one creature type with the creature you sacrificed. For example, if you sacrificed a Cat Wizard, you'll stop if you reveal a Human Wizard or Cat Soldier.