A strange, unique aspect of the Western Continent was that it lacked demonlings.
Back when the Sky-Heaven Dynasty was founded, an almighty member of the Demonfolk swept through the continent and took away all demonlings with potential for future growth. Later, the Sky-Heaven Dynasty instituted laws to strictly prohibit the slaughtering of demonlings. Instead, they were to be captured and offered as gifts to Amaranthine Greensura.
According to the intelligence reports of the Sun Moon Institute, all such captured demonlings ended up in the Hanging Mountain.
Over the millions upon millions of years which had passed since then, the population of demonlings in the Western Continent shrank and shrank to the point where they were essentially extinct. Any organizations who sought demon cores to augment spell formations or magical devices would need to surreptitiously acquire them from the Rich-Lush Continent.
Demon cores were about as precious in the Western Continent as spirit stones were in the Rich-Lush Continent.
Not even the elite students of the institutes in the Rich-Lush...