...There's something the locals call a shift. Most believe it to be supernatural, while I would prefer the term unexplained, but whatever it is, the Third Party is adept at using shifts to their advantage. Some areas outside the enclosure naturally have shifts, and evidently, not every person is compatible with every shift. People who venture into incompatible areas demonstrably have bad side effects. When drafting villagers, the Malnosso choose based on compatibility with the shifts in the area.