Based on Lu Shu's analysis, those that entered were daoyuan students, members of the heavenly network and soldiers.
The heavenly network had a standardized black coat, soldiers had their army uniforms and daoyuan students wore all kinds of clothes. Xi Fei mentioned before that daoyuan students would have to wear uniforms in the near future which Lu Shu could understand. Things like standardized uniforms would be a step towards establishing an identity. If every aspect was standardized, it would improve their mentality as a team.
Of course, there were others from other countries in this remains since the area was too large for every corner to be kept under surveillance. But Lu Shu believed that if these people were planning an attack, they wouldn't be dressed as casual as the students and not carry any weapons with them.
