Karthus, The Deathsinger

+1: Karthus deals 2 damage to up to 2 target creatures your opponents control. If you target only 1 creature he deals additional 2 damage.
-4: Until end of turn whenever a creature dies add {u} to your mana pool or give Karthus, The Deathsinger a loyalty counter
-8: Karthus deals 8 damage to each opponent and deals 8 damage to all planeswalkers and creatures opponents control