Bloodshadow Oligarch

Contract- Sacrifice a creature. (At the beginning of
your upkeep, each opponent may pay this creature's
contract cost. If a player doesn't, they violate the
contract.)
Whenever an opponent violates Bloodshadow
Oligarch's contract, reveal the top card of your
library, then put that card into your hand and
you lose life equal to its converted mana cost.