Story Spoilers: Nyarlathotep?

[Lightice]

...so he's like the Shadow?

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

I disagree about the inclusion of supernatural elements diminishing the effect of the story. After all, we have electric piggies, walking corpses, ghosts, sentient machines and a pig invasion to challenge our suspension of disbelief.

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.