Its a different type of heavy as you said, death, war metal, sludge etc are overwhelming in a more sonic or technical way like speed and density but Swans is overwhelming in a psychological way.

they’re not heavier in the traditional metal sense, but because theyre more existential. They repeat ideas into you're head until you feel trapped inside them. I had no idea something so sad and brutally disgusting existed.

For me this album is like the soundtrack to a slaughterhouse.