This is indeed possible.
But looking at it from another angle, the Abyss Prison's magical barriers have gathered the technologies of the Eight Great Churches. It's already the limit for ordinary people to break through one or two; wanting to decrypt them all requires the Eight Great Churches joining forces, which is simply impossible.
Therefore, the Abyss Prison can indeed be seen as an unbreakable sealing place.
"To what extent can you do it?" Hewinia asked.
"Reverse the sleep of the guardians inside and then enter," Edwin said. "Before the next batch of people change shifts, no one will notice that during this time, the Microsleep Divine Stele is only nominally operational; it's actually already ineffective. This time is enough for us to reach the depths of the Abyss Prison. Rest assured, I know this route too. When my student returned, I saw his memories clearly."
"And then?"
