So what is the purpose of the machine ?

[SlackerinDeNile]

The machine was possessed by some ancient bloodthirsty Mayan God from the Orb Oswald brought back from Mexico. (It also gets merged with some of Mandus' own personality at some point or something idk). It manipulates Oswald into killing his own children and re-purposing the butcher factory for mass slaughter. Because feeding on massive amounts of blood is what old Mayan Gods do, I guess.

Oswald is under the impression that he's doing good and "saving" everyone while creating a new race of pig people. But the pig men were only to serve the machine and the people were just being senselessly killed to feed the Orb/Machine blood.

"BLOOD FOR THE BLOOD GOD!"