I am new to BM and I am trying to find my way around. I currently own albums of early Emperor and early Immortal. I am especially taken with "Pure Holocaust" and "Battles in the North." Granted, there is probably no other band that sounds just like Immortal, but what are some other bands and albums that I should look into? Again: I would love something in the vein of "Pure Holocaust."
Some advice that will apply in many areas, without fail, over the years.
Every result has one cause; but every potential cause has infinite potential results. (The universe is larger than its parts, and so cannot be predicted, although any part can have its lineage traced.)
Kontinual's advice is good. All music has both content and form, and multiple forms can achieve similar expressions of content. They will not "sound like"
Pure Holocaust, maybe, but they will "feel like" what it expressed.
Graveland - The Celtic Winter
Gorgoroth - Antichrist
Enslaved - Vikinglgr Veldi
Burzum - Hvis Lyset Tar Oss
Anton Bruckner - Symphony Number 4
Camille Saint-Saens - Symphony Number 3
Ludwig van Beethoven - Symphony Number 1
Keep pursuing whatever vision of clarity you found in that album, in yourself.