After thinking about it, we shouldn't include Ghan-buri-Ghan in any of the decks. You say In Twilight is basically a rare, GBG is a R+, just like Glorfindel from the same P set.
I don't think there's really any need to replace 
Nazgul Sword for 
Nazgul Blade or 
In Twilight, after all you said the deck builds up burdens to get advantages and not to corrupt... and I don't see any advantages to be used with X burdens in any of those Twilight Nazgul decks posted, except for 
Nazgul Sword, 
Threshold of Shadow and (maybe) Twilight Enquea. Nazgul strike the sooner the better, and this sitepath doesn't help at all.
In absence of rare cards, twilight nazzies have a hard time focusing on working only one single goal by themselves: either wounding the ringbearer or adding direct burdens. So 3 burdens may be a very realistic goal... Let's think about this ideal scenario: Twilight Enquea + 
Fell Beast + 
In Twilight = a 15 strenght fierce minion. That may be awesome, but what for? Most of the time, 2 wounds on Aragorn and 2 on the ringbearer. Next turn opponent plays 
Hobbit Appetite for Destruction (or 
Hard Choice)... that's all folks!
1. Wounding the RB: 3x or 4x 
Resistance Becomes Unbearable can pave the way to Enquea, but those hard-to-build wounds must be added as soon as possible and must be preserved from healing. 
You Bring Great Evil, 
Orc Assassin and 
Under the Watching Eye should help on that purpose. The latter doesn't exert necessarily the ringbearer, but if a fighter gets exerted your chances of using The Witch's gametext are greatly increased...
(30 cards)
1x 
Morgul Skulker4x 
Orc Assassin1x 
Orc Cutthroat2x 
The Witch-king, Deathless Lord3x 
Ulaire Attea, The Easterling3x 
Ulaire Enquea, Ringwraith in Twilight3x 
Ulaire Otsea, Ringwraith in Twilight3x 
Fell Beast2x 
Nazgul Sword3x 
Resistance Becomes Unbearable3x 
Under the Watching Eye2x 
You Bring Great EvilKey Sites:
1 
Western Emyn Muil4 
White Mountains8 
Nan Curunir or 
Valley of SarumanProbably needs some tweaking. 6 Sauron Orcs + 11 Nazgul = 56,7% minions. Not a single skirimish event unfortunately, but it's focused on grinding Frodo instead. If there are 2 hobbit comps on the table, 
Orc Assassin can be a nice surprise (unless 
Weary From the Journey is added to this sealed). Lacks the Blade Tips too, so Otsea is just a twilight guy this time; those could be added to a Beatdown Nazgul deck from another serie.
2. Direct Burdens: This one is harder to build in the absence of Easterlings (but those can be neglected by RB Rangers very well). 4x 
It Wants to Be Found and 2x 
Drawn to Its Power should work, with pumps to overwhelm and to give 
Ulaire Otsea, RiT a chance to put that 
Blade Tip on Frodo...
(30 cards)
2x 
Morgul Skulker2x 
The Witch-king, Deathless Lord3x 
Ulaire Attea, The Easterling3x 
Ulaire Enquea, Ringwraith in Twilight3x 
Ulaire Otsea, Ringwraith in Twilight3x 
Fell Beast2x 
Nazgul Sword4x 
It Wants to be Found (or 3x, + 1 
Their Power Is In Terror)
4x 
Threshold of Shadow (or 3x, and an additional 
Nazgul Sword)
2x 
Blade Tip2x 
Drawn to Its PowerKey Sites:
Same as above
This looks more like a Beatdown Nazgul deck.... that's the objective here; 
Nazgul Sword makes a huge difference if 
Drawn To Its Power and 3 burdens are on the table. 
Sam, SoH with 
Rosie Cotton, HL can wreck it, so 1x 
Their Power Is In Terror could be added if The Witch King and Attea are found to be not enough. Those 
Wisp of Pale Sheen are out since they hardly would survive against a Rohan, Dwarf or 
Shoulder to Shoulder deck; they are more viable if played at the regroup phase with 
Peril (or Spied From Above), but that would need a bunch of Sauron Orcs with good vitality (
Orc Pillager for example)...
I like the idea of a 
Peril / 
Teeth of Mordor deck, maybe I'll build and post a deck in the coming days. Those wraiths would fit there very well, but not here unfortunately.