Conversation so far:
What is black metal?
Black metal is an extreme subgenre of heavy metal music. Common traits include fast tempos, a shrieking vocal style, heavily distorted guitars played with tremolo picking, raw recording, and more.
What is the music genre death metal?
Death metal is an extreme subgenre of heavy metal music. It typically employs heavily distorted and low-tuned guitars, played with techniques such as palm muting and tremolo picking.
What are some of Euronymous' beliefs about black metal?
Euronymous said that the term black metal can apply to any kind of metal so long as it is Satanic and heavy.
What were some of Euronymous' beliefs about death metal?
Euronymous said that the term death metal can apply to any kind of metal, so long as the band cultivates and worships death.
Did Euronymous have any other ideas about black metal besides the term applying to any kind of metal so long as it is Satanic and heavy?
Euronymous rejected bands like Immortal being called black metal, as they are not Satanists, but supported the band nonetheless.
What were Euronymous' feelings for bands if they were not Satanists?
Euronymous rejected bands like Immortal being called black metal, as they are not Satanists, but supported the band nonetheless.
Did Euronymous have any other interesting beliefs about black and death metal besides his other beliefs and non-Satanist bands?
Like many others in the black metal scene, Euronymous originally believed that black metal should stay underground.

Question: Did he change his mind about black metal being just underground?
Self-contained rewrite: Did Euronymous change his mind about black metal being just underground?