Aether Weaver

Dark Pact - When Aether Weaver enters the battlefield you may put a pack counter on target Horror, Demon or Demigod, if you do put one
on Aether Weaver.
At the begining of your upkeep lose one life for
each Horror, Demon or Demigod with a pack
counter on them.
Whenever you attack with a Horror, Demon or Demigod, they get +1/+1 until end of turn for
each Warlock with a pack counter on it.