I could fit the amount of misconception about black metal into the Grand Canyon. One of the single worst conversations I ever had on the genre was at a bar in Denton some years ago. I asked this self-proclaimed black metal expert if he was going to this Proclamation (very good Spanish black metal band) show in Austin. His answer still haunts me to this day, "nah man, when I listen to black metal I always do it alone. It is such a viscerally individual experience. I can't share that kind of catharsis with a crowd of people at a show." It was legitimately the worst answer to a simple, honest question I'd ever heard. I never spoke to the guy again. Worse yet are the Lords of Chaos types; the people who think black metal is simply a big game of "Varg says..."
One of the best collectives of black metal in the world is the Ross Bay Cult based in western Canada. The bands from this group include Conqueror, Antichrist, and the almighty Blasphemy. Blasphemy started in 1984, that puts them on par or before much of the bands that often get labeled as essential black metal, only they did it better. Blasphemy is so influential to black metal that the entire raw / bestial realm of black metal owes itself to them. Bands like Proclamation, Revenge, and Black Witchery would not exist without the Blasphemy influence. Here's how you can tell if someone doesn't know anything about black metal. Play them Blasphemy. See what they say. If they try to dismiss Blasphemy as a death metal band or a grindcore band or anything not a black metal band, they are false. Blasphemy is at its essence a black metal band. Violent, ill-intentioned, and sketchy (except they don't have to write a book about it; the band's mythology is just that, a mythology, what you've heard but can't prove about them is endless). Blasphemy describes themselves as black metal skinheads. I know what you're thinking, they're Nazis, right? Blasphemy's guitar player Caller of the Storms is black. A member of Destroyer 666 once got punched out by a member of a Blasphemy for asking them why they had a black guy (they didn't actually say black guy) in the band.
When you listen to Blasphemy, you gain an understanding for black metal that has been seemingly lost on so much of the genre's constituents. For some reason in the USA, people interpret black metal as an acoustic vehicle to cut yourself or to be brooding. That isn't it at all. Black metal is about hating the world and attacking it for being so awful. Blasphemy's brand of black metal enables that. Listening to them will make you throw a punch and not only embrace your hatred, but also act on it.
I don't know the facts about Blasphemy, only the stories and that's really what a mythology is about. Included is both their albums and their demo.