Xyru Specter 
Summon — Specter
Flying Whenever Xyru Specter deals damage to an opponent, that player discards a card unless they challenge you. If challenged, and you show them two black cards in your hand, they must discard two cards.
Legality
standardNOT LEGALpioneerNOT LEGALmodernNOT LEGALlegacyNOT LEGALvintageNOT LEGALcommanderNOT LEGAL