The state of the security room was quite a shock for Arter and Maximilian, especially since it was already well established how incredibly sturdy and resilient everything inside the ruins were. Even if they wanted to, the Neophytes would not be able to put a single scratch on the wall.
Maybe Arter might be able to do that now that his ability had upgraded, but since he had not tested his limits yet it was hard to say.
Nero and Gabriel, on the other hand, took it in their stride. Nero especially became a lot more relaxed since the possibility of their actions being uncovered in the subsequent years was reduced. After all, if nothing else, just getting his hand on all six of the required keys would not be an easy task, which is why he was prepared for this to take years, if not decades. He strongly suspected that this would definitely be worth it.