Above the towering walls of North Pass, Lei Dong calmly surveyed the various defenses. This defensive stronghold had been cleverly designed in the shape of a gourd. At the very front stood a wall several miles wide and over a hundred zhang tall. Unlike the design of mortal cities, this wall had no gate. Its surface was covered in runic inscriptions, clearly meant to reinforce its defenses. Below the city walls, countless spikes and traps made it difficult to cross.
It was worthy of the work of cultivators: the wall was more than ten zhang thick. Forts had been built along its top, where cultivators could rest and tend their wounds, or unleash spells through narrow firing slits. Farther behind the wall, a dozen or so towers had been erected at some point, each mounting a fearsome cannon.
Lei Dong was naturally familiar with these spell cannons. The Netherworld Warship of old had carried one, as did the Flying Boat he was on now. Typically, these cannons used the exceedingly intricate formations engraved inside their barrels, powered by Spirit Stones, to fire a spell with power comparable to a Golden Core Stage Cultivator's full-force strike.
Just two thousand years ago, spell cannons had not even existed. It was the Mechanism Sect of Kang Prefecture that, two thousand years ago, had taken inspiration from the earthen cannons used by mortal nations to attack and defend cities. Combining that inspiration with ancient Mechanisms Art, they had designed something resembling a magic treasure, yet wholly unlike anything in the magic treasure system.
In a short time, they had gradually spread even to places like Zhao Prefecture. Of course, Zhao Prefecture was still far behind Kang Prefecture in the widespread use of spell cannons. At the very least, most Flying Boats were not equipped