leviathan but xasthur is way better. and none of these bands are ambient. you are saying ambient but you mean atmospheric
I can't stand Abruptum either but I wouldn't really class Hate Forest(which I also love) as ambient black, or any other band listed either, because I don't really class metal as ambient, and even if there was, Abruptum would be the closest thing to it as it has black metal influence and atmosphere.
Anyway, Negura Bunget and Deathspell Omega are kind of similar to WITTR, llamaking.
try:
drudkh
alatyr
velvet cacoon
striborg
darkspace
hate forest (if you like the working in a third world prison feel)
as far as atmospheric bands
i agree that's why i wasn't listing ambient black
NOT "Naglfar"..."Nagelfar"...veryyyyy different (one with the 'e' is a shitttttload better).
Also don't listen to Lord Kur. A ton of black metal is very much ambient-influenced and he's basically just a moron a good deal of the time (hence being banned). If you are a Xasthur fan, check out I Shalt Become, Velvet Cacoon (Genevieve as mentioned), Krohm and Marblebog.