The Whisper

The most dreaded symptom of Mormo's corruption. It can come in different forms and most of what is known about it is still nothing more than speculation.

Whisper-Test
To recognize the effects of the Whisper early on, a number of psychological tests were developed to detect it. A test is conducted in form of an interview, in which the suspect talks about themselves and their recent feelings, goes through free association tasks, is asked to tell short stories about cryptic pictures, needs to continue telling a story the interrogator started and so on.

Factors like being influenced by mental magic or mind control, or even something like a soulbond to another being, can lead to false-positives.

Interrogators who know how the results need to be analyzed can't be tested themselves, because they know how to lie to produce the desired results. This is why only few are trained to become Whisper-interrogators. For reasons unknown, people who are afflicted by the Whisper in the late stages also know how to bypass the test.

Treatment
It seems possible to prevent further progression during the earlier stages. The victim must ignore the Whisper, either through somehow being able to differentiate their own thoughts from its influence and not listening to it, or through the help of drugs. In later stages, only drastic measures like Feeblemind or destructive surgical operations can prevent further progress, although this will always impact the victims cognitive abilities.