Curse of Chaos 
Enchantment — Aura Curse
Enchant player Whenever a player attacks enchanted player with one or more creatures, that attacking player may discard a card. If the player does, they draw a card.
Legality
standardNOT LEGALpioneerNOT LEGALmodernNOT LEGALlegacyLEGALvintageLEGALcommanderLEGAL