Talking about influence is hard when I don't know much about musicology/music theory/guitar playing, and I'm somewhat sympathetic to the idea that extreme metal is doing something fairly different (Mike Scalzi has a good article where he points out that listening to a lot of grindcore, death metal, and black metal is more like listening to ambient or noise because it's not about awesome riffs/catchy melodies), and I don't like sweeping generalizations. But I feel like the book on how to play the electric guitar with distortion (and how to make rock music) was written by blues musicians and it's hard to escape that, even though some bands have ditched conventional song structures or even writing melodies. And genres are big tents, there's a lot of blues based around structures very unlike pop songs, and I don't have any trouble saying that Sahg and Kodiak are playing the same style of music with, at root, the same influences, even if Sahg are writing 'pop' songs with vocals singing choruses and Kodiak definitely are not.
https://www.youtube.com/watch?v=InG7SjWKtT4 alan lomax's prison blues recordings
https://www.youtube.com/watch?v=au7qnCiFdog kodiak
https://www.youtube.com/watch?v=b-CF7vfXy2U sahg
Also agree that the acceptance of Damnation was a quality thing.
