Apprentice Destroyer is not a band but rather a project led by Steve Peacock (also member of Ulthar, Pandiscordian Necrogenesis, Pale Chalice and Mastery), who is assisted by a number of guitarists and a drummer. Having 4 guitarists might explain the incredibly dense guitar work.
Apprentice Destroyer released two other records in the past, but this is the first time I heard of them.
But how does it sound? Well, if you can imagine music as mathematics, riffs as squares, triangles, octagons, ... then you're pretty close. It sounds like musical Tetris, with riffs tumbling over each other, everything fitting perfectly together. Hmm, that didn't make sense, did it... Musically, it leans a bit towards Krautrock, infused with Liturgy. The songs are very repetitive and hypnotic, most of the time starting with one (dissonant) riff, and then building up with drums and additional guitars thrown in.
Expect no blast beats, this is solid mid-tempo work. A nice touch is the metallic guitar sound, which sometimes reminds me of Big Black (may they rest in peace). In any case, the production is crystal clear, which helps convey the power of the songs. There's also two short modular synth intermezzos, nice and fat, and slightly detuned, just like an analog synth should sound. This
obviously adds to the Krautrock-ish sound.
Even if I compared this music to mathematics, don't expect a cold or Djentish sound. "Permanent Climbing Monolith" is able to take me on an immersive emotional rollercoaster ride. My only complaint is that, even at 42 minutes, it's too short... and that's high praise.