With the rotation out of the Fellowship block and the subsequent loss of Morgul Gates, things were looking grim for the Nazgul. At a pricely average of 6 twilight per Wraith, they simply were too expensive to be effective. That is, until Dark Approach.
Dark approach is Morgul Gates.... only better. With the ability to control the site path on both the Free Peoples and Shadow side, you can easily deploy a 4 forest stie path within the first half of the game. From that point on, each of your Nazgul comes at a hefty discount using this card. With the new Black Lord or the Toil 2 Captain of the Nine Riders, your Witch King and Nazgul will be able to drop on the table in groups of 4 at least, leaving things looking dark for your opponent!