"The second conclusion: triggering multiple alternative spaces comes with substantial consumption. However, this consumption decreases as the alternative space persists over time."
"For example, a large alternative space consumes 100 spirit essence in the first year, possibly only needing 50 spirit essence in the second year, decreasing to 1 spirit essence by the hundredth year, and merely 0.1 spirit essence by the thousandth year."
This is because the ability of multiple alternative spaces must counter the inherent physical laws. It's like a spring which slackens over time, eventually losing its tension completely.
This also explains why creatures of anomaly, such as [Monster], are reluctant to change locations.
Because moving costs them more spirit essence.
"How powerful is the myth of [Monster]? A multiple alternative space can encompass a diameter of 300,000 kilometers, capable of swallowing the entire Northern Territory."
