Damping Engine
Urza's Legacy — rare
Artifact
Damping Engine rulings:
2008-08-01: A player affected by this card can sacrifice a permanent any time they could cast an instant. This is a special action that doesn’t use the stack and can’t be responded to.
2008-08-01: A player can only sacrifice a permanent to end this effect if they have more permanents than any other player, and they haven’t already sacrificed a permanent to end the effect this turn. The ability to sacrifice a creature is granted by the same effect that is being ended.