Story Spoilers: Nyarlathotep?

[Alardem]

...so he's like the Shadow?

Does the Shadow require regular human sacrifices from people who try their hand at interdimensional travel?

...yes. At least, that's what Alexander, man from another world, had convinced Daniel into believing. Anyways, they're both 'guardians' against things humanity was not yet ready to harness.

You misunderstand me. Ofcourse there are supernatural elements in the story. My point is that a human mind is the instigator of it all, not some otherwordly monster. Mandus used the Orb and bent it to his will and created the Machine of his own free (albeit batshit insane) will, no-one else compelled him to do it. The dissonance between his actions and intents eventually tore a piece of his own soul living its own life inside the machine; as the Engineer puts it: "before you I was but a rotting piece of architecture".

That is the real horror of A Machine for Pigs; it's not some eldritch abomination compelling people to commit evil deeds, they are just as good at it, if not better. In The Dark Descent Alexander, a monster from another world, is deeply disturbed how someone like Daniel can so eagerly torment his own kind. Mandus takes this to another extreme, since there is no-one to tell him to commit all his atrocities, he does them all by himself, bending the cosmic forces to serve him in his pursuit, rather than vice versa, all the while convincing himself that he's doing the world a service, until the cognitive dissonance cuts too deep and the Engineer is split off from him.

I agree with the notion of the true horror of Amnesia coming from the depths of evil humans are capable of. I'm just saying that it's compatible with hints that these actions could be derived from a skewed perspective of the world.

Again, the vision Mandus had of the future was skewed towards displaying upcoming evils of imperialism, mechanized suffering and (presumably) his own hand in such acts. He failed to understand that it was possible to resist these horrors without resorting to violence, pain and slaughter. He didn't change his ways at all - he simply continued his sins to their bloody conclusion. (Scrooge would be disappointed.)