Blasphemy and Goatlord, Sadistik Exekution could be mentioned as an influental band if it's about the forming of the black/death subgenre.
This style had no fixed scene, similar bands just like appeared randomly at various locations and mostly pretty rarely. Similar to the mentioned others, Sadistik Exekution played very noisy and absolute compromise-less blasphemic brutality. Sound quality was secondary, but their second full-lenght album had a larger progression in that way after "The Magus". It's hard to find out where they turn unserious and immature directly, and when things should be taken more seriously. In this style it's not hard for a band to become it's own parody, but probably they just "didn't give a fukk" about the whole thing, just wanted to play some noisy, disturbing satanic insanity. Unlike most of others in this endlessly exaggerated style, they tried to operate with atmoshpere too, but that's also some upsetting noise only, no need to be afraid of any light melodies to appear, that may break the balance of disharmony. Anyway, "We Are Death... Fukk You!" counts as a remarkable black/death metal classic.