Building a second-tier territory wasn't as easy as Du You had imagined. He hadn't anticipated that many buildings would require higher-level blueprints to upgrade.
Somethings like these were not readily available in his homeland.
However, some buildings could still be upgraded. First and foremost were the second-tier Rune City Walls.
Du You already had the blueprints for the second-tier Rune City Wall, but constructing the wall was somewhat challenging. It required not only workers, but also the participation of mages, regardless of whether they were professionals or not.
"It's a good thing I trained a group of mages earlier, otherwise, the city wall couldn't have been built. We also need magic dust. The materials from the magical beasts we hunted before are useful for creating it."
