The Wise Sovereign listened and nodded, seeming to agree with Angel, though he was no longer as surprised as he had been at the start.
"From these clues alone, you thought of a magical energy array node. You have quite an imaginative mind."
Angel smiled and walked straight to the low cabinet beside the bed. As he searched through it, he said, "Besides that, I have another guess."
The Wise Sovereign narrowed his third eye. "Oh? What guess?"
Angel said, "Energy cannot arise from nothing. Since this is an energy node of a magical energy array, where does that energy come from?"
At this, the Wise Sovereign's expression paused before he continued, "Where do you think it comes from?"
Angel opened the low cabinet and took out a small wooden box with an exquisitely crafted appearance. It too was made of Deepsea Wood.
"Generally speaking, the energy source for most magical energy arrays comes from magic crystals. But for magical energy arrays fixed in place for long-term operation and covering a large area, magic crystals can sustain them for a short while, but over time, the consumption becomes terrifying. That is when one must consider energy circulation."
Angel opened the wooden box, glanced inside, and continued.
"A magical energy array on the scale of the underground sewers would certainly have needed to consider energy circulation. As for how that circulation was established and the energy problem resolved, we need to discuss it separately for Abyss City's prosperous era and after its decline."
"During its prosperous era, there were many underground residents, naturally bringing in greater profits. At that time, even using magic crystals as consumables meant more came in than went out. Thus, prosperous-era Abyss City had many options, and resolving energy circulation was not a problem at all. We