Threat Level refers to the readings detected by the Aberration Index, which describe the level of power that Notre have and the level of danger they possess to society. The readings are encoded into the Index which compiles data about the specific Notre that it is registering, after which it gives an estimated calculation in relatable terms that is converted into numbers of an unspecified unit. This resulting number is the "Threat Level" which describes the potential danger the newly registered Notre possesses. Threat Level is generally an equivocal term that describes the level of mystical energy, magical powers and physical strength an individual has.
The use of the threat levels is to register and calculate the potential danger that any Notre possess. This is done so that the World Government can take the proper necessary precautions in dealing with them. Whether it be sending troops to arrest them, sending the World Guard to battle them, ordering a large scale man hunt or using more powerful weapons and resources. It is a system created to assist the Lyrics and give them both a sense of security and a way to understand the potential limits of their opponents.
- The threat levels draws inspiration from Akira Toriyama's Dragonball Z power levels and One and Yusuke Murata's One-Punch Man's disaster levels.