Because...
The Abyssal Demons would definitely plant evil Fallens among the ordinary people in Jiang City.
There were many of them, and they were not very powerful. They were usually inactive and occasionally came out for lighter missions. They also were on a one-way communication, mainly the demon contacting the human, so it was difficult for the spies arranged by humans to find out their specific identities.
They were not like the spies in the Professional Alliance. Their identities and positions were too important, and they often leaked information to the Abyssal Demons. They left all kinds of clues, which made them easier to find.
So,
The higher-ups in the Professional Alliance had considered this from the very beginning.
These low-level Fallens might go to the college entrance exam venue with a suicidal attitude when the abyss was attacked. This would affect the safety of Lin Ye and the other students.
