Only a bit over two weeks have passed since Leon left for the underground expedition, but the Capital's rate of development was staggering and seemed to have increased exponentially.
The construction of the railway and strengthening of commoners via the breathing technique had indeed greatly boost productivity and work efficiency, but the greatest factor was not related to Leon.
The World Tree had only just started introducing spirit energy to the world. It would take some time before the spirit energy spread to the Capital.
Under normal circumstances, the most talented of miners had only reached the 3rd layer of the Body Tempering Realm. This had indeed boosted the acquisition of raw ores greatly, but half the contribution of raw ore acquisition was actually due to earth-users.