IMHO, Shadow Bolt is a bit underpower. With 4 removal cards (2x soulfire, 2x mortal Coil) would be enough.
You can change it for another Harvest Golem, Knive juggler, Dark Iron Dwarf or Void Terror. If you think that you need more removal, even hellfire could be an option because it has synergy with Nerubian Egg/Haunted Creeper and hit the hero too.