Sure, if you are content with a mediocre deck. I understand the "coolness" factor of having a monocultural deck, but what is the harm of having characters that will make your deck better?!
Here's the biggest problem with
The Witch-King, Lord of the Nazgul and a Twilight
deck (or at least, as it is currently set up). Your cards all have relatively high twilight costs, and
Lord of the Nazgul has a big target printed on his back.
Think about it like this. Let's say you played all five of your minions at a time. Clearly The Witch-King, the
Lord of the Nazgul is going to be the guy that your opponent focuses all of his skirmish events, etc. on. The
Lord of the Nazgul is a great card, I agree, but its power is almost
too good in that the Free Peoples' player will work hard to make it not happen.
And there are several ways in Towers Block, too.
Mablung, Soldier of Gondor, discarding hobbits, cancelling skirmishes, all of that means that you can't use his badass ability.
is heavily played in Towers Standard and they eat Nazgul for breakfast.
All of your minions are expensive. Having a low-cost option or two, like
Gollum, Stinker,
Morgul Skulker, or even
Easterling Lieutenant means that you can play more minions and hopefully win more skirmishes.
On a
note, why aren't you using
Ulaire Toldea, Winged Sentry? Seems like he'd probably help more than
Messenger of Morgul...
-wtk