As I understand it all necros regardless of race can visit the guild in
Neriak. Thats the GUILD, however, guards may still KOS ceretain races
so conn them. The guild is guarded by Ghouls who will KOS most non DE
who try and enter there, as well as the wandering pets who may take
exception to other races. Use invis to enter, conn guards from a
distance, if they aren't immdiately hostile cast invis to undead once
you enter the third gate of neriak and you should be able to get past
the Ghouls. Just remember to recast it after you visit the guild when
trying to go past the ghouls again. THe secret here is to conn
everything before getting within attack range. Also, if you've been
killing Crushbone Orc don't even go into Nektulous forest, the Indigo
Brotherhood is the Dark Elves so your faction is probably in the KOS
range.

Slortar on Karana