After the underground passage was opened, it became much easier and safer to return to the Capital. For safety reasons, Du You didn't reside in his own city but chose to return to his dwelling in the Capital.
Similarly, it was easier for him to search for things in the academy and to acquire news about different worlds and various resources. His recently established city was still lacking in several aspects.
As for entering the city, it was too easy. The city administrator could directly notify him. And if he wanted to go there, he could first enter his territory and then reach it through the passage. The return was troublesome, but the time spent traveling there wasn't much.
On his way home, Du You hadn't even set out when he received a great item.
It turned out that in the Giant world, where the Night Giants originally resided, a vein of dark ore was discovered, yielding a tier-four Dark Element Stone. This item was useless to others, but he had been seeking it all along.
