Losing control over the barrier?

The black stones taken out by the three groups looked exactly the same as they didn't think much before breaking it.

'Swoosh'

As soon as they broke those black stones, the black mist started coming out of their hands as it slowly covered the barrier around Silverstone town.

"Let's get prepared while the black mist covers the entire barrier."

Soon, the heads of the three groups ordered the young men and women to get ready.

"Except for the girl named Beck, kill everyone."

This was the next order that came out of their mouths and everyone nodded their heads with excited smiles because the reason they volunteered to this mission was because of this.

"But how can we find her, teacher?"

One of the young men asked the middle-aged man as he eyed the black barrier in front of him.

"Haha…don't worry. As soon as the barrier is covered with the black mist, you will find out."