The Corvus Killer

+1: Target opponent discards a card. If a creature card is discarded this way create a 1/1 black Bird creature token with flying.
-X: Destroy target creature or planeswalker with mana value X. If a planeswalker is destroyed this way put a loyalty counter on The Corvus Killer.
-7: Exile target planeswalker card from a graveyard. The Corvus Killer gains all loyalty abilities of that card.