Archfiend of Despair 
Creature — Demon
Flying Your opponents can't gain life. At the beginning of each end step, each opponent loses life equal to the life that player lost this turn. (Damage causes loss of life.)
Legality
standardNOT LEGALpioneerNOT LEGALmodernNOT LEGALlegacyLEGALvintageLEGALcommanderLEGAL