Story Spoilers: Nyarlathotep?

[Alardem]

I'm not sure if sacrifices actually did anything to ward off the Shadow - that was just what Alexander led Daniel to believe, and for all we know that could have further incurred its wrath. But I agree about the Machine likely being far more effective at harvesting 'Vitae' than anything Alexander had available to him.

I'd just go with different objects having different properties. The Orb can grant you power but kill you if you misuse it, the Soapstone (owned by Justine) can makes you obsessive and sociopathic, and the Stone Egg can grant you twisted visions of the future. Making the world predictable/logical goes against the appeal of Lovecraftian fiction.

It's interesting to note that in one of the unused endings, the Stone Egg would apparently hatch and unleash a 'great light' implied to be like atomic fire. Perhaps this is the cleansing that Mandus hoped to achieve.

EDIT: Could it be that Mandus himself unknowingly fulfills Nyarlathotep's role? He enacted the will of greater forces (the future, or perhaps an Aztec deity), was deceptive in order to garner followers (disguising himself as a philanthropist), and seeks to wipe the earth clean of humanity so that another race (the Man-Pigs) can dominate them.