Seductive Siren

X equals any amount of life you choose to pay
when Seductive Siren comes into play.
If target player has a creature in play, you may
{t} Seductive Siren to look at that player's hand.
Choose a card in his or her hand. That player
must discard that card or sacrifice a creature.
When Seductive Siren leaves play, the player with
the lowest life total sacrifices X creatures.