I would throw in at least 3
Messenger of Morgul, if it would be standard legal, but unfortunately it is not (man... it would PWN in this deck, I have to creat an expanded version

). I'm trying to squeeze in the 3rd
Dark Fell About Him, but I just can't find the spot... But I think 2 is fine too, because I don't really want to play it, unless I can corrupt the rb with it, and against some deck, finding a nazgul with 3 vitality in the regroup is not so easy.
EDIT:
Just a recent thought.. What do you guys think of
Throne of the Dark Lord? I already play
Mount Doom, and Nelya can change to it any time, so it's like 2 burden for 2 twilight.