Anomalies are the core supernatural threats in the world of YiHuan. They are anomalous phenomena produced when reality is distorted, manifesting in various ways — some alter physical laws, some twist spatial structures, and some can even affect the flow of time. Anomalies typically appear suddenly in the city, causing serious impacts on the surrounding environment and residents.
Hethereau is a high-incidence area for anomalies, which is why the Bureau of Anomaly Control established its headquarters here. According to Worheimer Index monitoring, anomaly activity levels vary across different areas of the city, with certain regions (such as Groth Island and Illusion Town) experiencing abnormally frequent anomaly activity.
One of the primary duties of Espers is to respond to and handle anomalies. The ETD-4 team is dispatched to various anomaly sites for investigation, containment, and elimination. Dealing with anomalies requires Espers of corresponding attributes working together, as exploiting attribute weaknesses can effectively reduce anomaly intensity. If not addressed promptly, anomalies will continue to expand their range, ultimately leading to Encroachment — the permanent erosion and alteration of reality.