I understand what you are saying, but I am looking for a clear and unambiguous definition. There is no reason why a certain emotional response could not be part of it, if fact, that could make it even better.
What about Drudkh? They are definitely black metal, but they have a warmth in a lot of their music.
With a genre as diverse as black metal, how would you distinguish what belongs in it from what does not? For instance, to me, a lot of the first wave bands (except Bathory) sound closer to thrash and death metal than most black metal. Would you include a historical connection to/inspiration from earlier black metal bands as part of a definition of what makes a particular piece of music black metal?