>>534539031
Star God = C'Tan = very powerful plasma lifeform that lives inside some stars, and feeds off stellar energy. Necrons made a deal with C'Tan but came to regret it.
Nomos was supposed to be the ship's AI from the Age of Technology, hence why the text "nom_OS" appears when you first encounter him. He was meant to be an awakened operating system, linked to Pasqal's quest for forbidden knowledge.
But they dropped this and now he's some sort of sci-fi bullshit "shard of a shard of the C'Tan"