Skemfar Shadowsage 

Creature — Elf Cleric
When this creature enters, choose one — • Each opponent loses X life, where X is the greatest number of creatures you control that have a creature type in common. • You gain X life, where X is the greatest number of creatures you control that have a creature type in common.
Legality
standardNOT LEGALpioneerLEGALmodernLEGALlegacyLEGALvintageLEGALcommanderLEGAL