Pox [Ice Age] Island Set: Unlimited Edition Type: Instant

Set: Unlimited Edition Type: Instant Rarity: Uncommon Cost: {B} As an additional cost to cast this spell

Set: Friday Night Magic 2001 Type: Instant Rarity: Rare Cost: {1}{U} Look at the top four cards of your library

Set: Morningtide Type: Enchantment Rarity: Rare Cost: {1}{G} Whenever a creature enters the battlefield under your control

If you do and they guessed wrong

defending player sacrifices two permanents

Pox [Ice Age] Island Set: Unlimited Edition Type: InstantSet: Ice Age Type: Sorcery Rarity: Rare Cost: {B}{B}{B} Each player loses a third of their life, then discards a third of the cards in their hand, then sacrifices a third of the creatures they control, then sacrifices a third of the lands they control. Round up each time.