As for why it was the Black Emperor, the first step of changing class, no matter the profession, was to merge with pollution and make one's originally pure "spirit" impure.
Once the pollution had been digested, one would stand at the pinnacle of one's current rank.
Take the Empress of the Empire, for instance. Five years ago, she took another step forward and advanced to become the White Emperor.
It was precisely because of the Empress's advancement that the Empire, having already reclaimed three provinces, launched another war of expansion.
However, there were also rumors that the Spirit King of the Myriad Spirits was close to advancing, or had perhaps already advanced. The reason he was ignoring the Empire now was that he wanted to surpass the fifth rank in a single stroke, ascend to the heavens and become a god, and enter the Divine Realm, whose existence was unknown.
Then use that power to utterly destroy the human Empire.
And speaking of it, the King of Myriad Spirits had a slight connection to Li Xun. Li Xun's profession was specially effective against monsters.
According to the human Empire's classification, the King of Myriad Spirits was also a monster.
The King of Myriad Spirits' true body was a mutated willow tree.
It was said that more than thirty years ago, that willow tree had already grown several hundred meters tall, blotting out the sky and sun.
In the early days of the war, the Empire had even deployed nuclear bombs whose technology was still immature. Yet they only destroyed some of its branches and failed to harm its roots at all.
In fact, the high-energy radiation produced by the nuclear explosions greatly spurred its growth—an artificial fertilization, so to speak.
This evolution of the Myriad Spirits proved something in a