When Iver and Cardinal Galatea arrived at the Spirit Tower, they saw that it was already enveloped in a dim-yellow barrier.
It should have been a preservation spell cast by the lich Grunewald. Judging from the preservation spell alone, Grunewald was indeed inferior to Insect Amber Master.
However, with the support of the Amber Angel's spine, the barrier's sturdiness had already exceeded the energy limit of the Sixth Level in the Material Realm.
Unless the Fallen Angel acted personally, it would be quite difficult for the Greater Demons to break through this barrier alone.
It wasn't impossible to open... it would simply be very exhausting.
After all, the Path of Transcendence excelled at escaping common sense and breaking through limits.
If the demons began the ritual, they would need at most one week to break through this seemingly impassable perfect barrier.
...However, considering that there weren't many people inside and that they had voluntarily adopted this passive, self-isolating stance, the demon army couldn't be bothered to attack the Spirit Tower. They simply went around it. After all, there were still many things to deal with outside.
It was like a multiple-choice question whose difficulty rivaled that of the final problem on an exam. Clearly, there was no need to waste time on it before finishing the questions that came afterward.
If the ruthless people inside were forced into a desperate corner, everyone might end up dead once they came out.
Thus, thanks to an accidental stroke of luck, the Spirit Tower survived the first and fiercest wave of the demonic tide.
However, it was obvious that the Spirit Tower's defenses did not consist merely of putting up a barrier and waiting to die... Someone was constantly monitoring the outside world.
Not long after Iver arrived, the current Vice-Headmaster, Adolf, hurried