The Lady, Lifetaker

Whenever a creature enters the battlefield under
your control or whenever a creature dies, each opponent sacrifices a creature and loses 1 life.
You gain life equal to the number of creatures
that were sacrificed this way.
Hexproof, deathtouch, lifelink.
{t}, Sacrifice another black creature: Search your library for a sorcery card with converted mana
cost less than or equal to sacrificed creature's
power.