The Orzhov Syndicate

Extort (when you cast a spell, you may pay {w/b}. If
you do, each opponent loses 1 life and you gain that
much life.)
You may pay any additional {w/b} to extort.
Instant and sorcery spells you cast have Haunt.
(when this spell is put into the graveyard during its resolution, exile it haunting target creature.)
Creatures you control have Afterlife equal to
their power.