+Kaervek (6)
Whenever an opponent casts a spell, Kaervek the Merciless deals damage equal to that spell's mana value to any target.
Other creatures get -1/-1.
Kaervek's Hex deals 1 damage to each nonblack creature and an additional 1 damage to each green creature.
Destroy target creature with mana value X. If that creature dies this way, Kaervek's Purge deals damage equal to the creature's power to the creature's controller.
As an additional cost to cast this spell, sacrifice all permanents you control and discard your hand.
Target player loses 5 life.
As long as Kaervek's Torch is on the stack, spells that target it cost more to cast.
Kaervek's Torch deals X damage to any target.
more to cast.