Vampirism 

Enchantment — Aura
Enchant creature When this Aura enters, draw a card at the beginning of the next turn's upkeep. Enchanted creature gets +1/+1 for each other creature you control. Other creatures you control get -1/-1.
Legality
standardNOT LEGALpioneerNOT LEGALmodernNOT LEGALlegacyLEGALvintageLEGALcommanderLEGAL