Malfegor | Magic: The Gathering
Formats Malfegor is Legal in
Official Oracle Text for Malfegor
When Malfegor enters the battlefield, discard your hand. Each opponent sacrifices a creature for each card discarded this way.
Official Rulings for Malfegor
2/1/2009 : After you discard your hand and the number of creatures each opponent must sacrifice has been determined, each opponent in turn order, starting with the player whose turn it is if that player is your opponent, chooses which creatures he or she will sacrifice, then all the chosen creatures are all sacrificed at the same time.