Pillar Tombs of Aku 
World Enchantment
At the beginning of each player's upkeep, that player may sacrifice a creature of their choice. If that player doesn't, they lose 5 life and you sacrifice this enchantment.
Legality
standardNOT LEGALpioneerNOT LEGALmodernNOT LEGALlegacyLEGALvintageLEGALcommanderLEGAL