In the seven years since 2009’s Gin, the Colorado duo swapped half its lineup—ex-Lord Mantis frontman Charlie Fell is doing the snarling now—but that’s not all Cobalt changed. Once recognizably black metal, their harrowing sludge now wades waist-deep in gunk-encrusted hardcore, Tool’s open-spaced art-grunge, the sadistic nihilism of Swans, and even primal roots forms. “Hunt the Buffalo” and “Beast Whip” both open as lumberjack-shack blues, “Breath” shimmers like forest-folk Led Zeppelin, and the lone voice on “Iconoclast” is a sampled Ernest Hemingway.