optionthree
Better than the first two
That is a very vague way of talking about black metal is combined with other genres. Name some bands, because usually most of those bands that combine black and death are really just playing old school black metal. I fail to find any Avant-Garde Black Metal bands; that would involve heavy amount of unorthodoxy in the composition. Maybe Blut Aus Nord or Deathspell Omega would fall under that term. I do agree that most of the experimental bands are much more interesting in terms of the current scene but they do not touch Darkthrone, Burzum, Mayhem, Bathory, etc.
By avant-garde, I mean bands like Dødheimsgard, Negura Bunget, Arcturus, Virus, etc. I'm really not familiar with DsO or BAN so I can't comment on them, but I don't see the appeal in an album like Transilvanian Hunger. It's undeniably monotonous and lacking any element that really makes me want to listen to it more than once or twice.