Blame!, Vol. 2 by Tsutomu Nihei

A stoic lone wanderer pushes deeper into a vast, nightmarish megastructure in search of humans who carry the elusive Net Terminal Gene, cutting through hostile automated defenses and encountering fragmented survivor enclaves; along the way he forges a wary alliance with a damaged but brilliant cybernetic scientist, and together they confront the city’s monstrous architecture, inscrutable systems, and the brutal logic of the Safeguard that relentlessly hunts any intruder.

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