Going underground, the group felt a sudden drop in temperature, and they currently were now walking to a different part of the prison which had pristine white walls.
Instead of the usual iron bars that prison jails typically looked like, that part of the facility had reinforced glass tinted with black instead.
One might think they were fragile or less sturdy than iron bars, but that definitely was not the case.
If it was, the prisoners inside would have escaped.
"This is Second Ward, if the prisoners on the First Ward are those individuals who are slightly stronger than regular humans or Level 1 acolytes, this is the place where Level Two acolytes are kept. The prisoners in this place varies. They could have breathing techniques, or capable of spells, but they all had cultivated in a cultivation method at least."
Carl could hear their footsteps inadvertently echoing while they continued to walk at the center of the prison.