black-demon-skull

ok i pretty much think this card sucks at least the casting cost. the effect is pretty good flying 4/4.
ok even if you are a n00b you should be able to see that his card drawing ability generates huge card advantage. (draw a card at the end of an opponents turn leaving niv to block)
this in mind you should see the 2 dam your opponent gets in a turn. (killing him in at a maximum of 10 turns)
there are better fliers simic zeppelid (dunno real name) 3/3 for four.
remember couriosity + niv means instant death in almost any situation.