Su Chengyu had indeed read about Beiming Black Stone in the books left by his grandfather. Beiming Black Stones are produced in the far, extreme north, a place full of uncertainties and harsh conditions. The book mentioned that the far north was a place full of dangerous monsters and beasts, so powerful that even cultivators of the Hollow Realm who ventured there were in great danger.
According to the geography books Su Chengyu studied, The Bei Luo Empire, which borders the northern part of Xia Country, is a vast country with the largest territory in the world. However, much of the northern part of the Empire is a barren land with harsh climate conditions, making it hard for humans to survive.
Thousands of miles beyond the North Pole of the Bei Luo Empire lies a deep, unfathomable black sea. This sea is referred to as the Dark Sea in geography books.
