According to Donna, there were three soul barriers in Orchard Square.
The first one was a detection barrier, likely set up by the Black Soul Scout to avoid unnecessary trouble. It ensured that only ordinary people or martial artists could enter. Anyone who had cultivated their soul would disrupt the rules of this private paradise.
The second barrier was an illusion-based one, directly affecting a person's soul to blur the line between reality and illusion.
The third barrier was the most intri