Throughout the Five Continents, one would be hard-pressed to find worse offense than demonic collusion. No matter how bold, the Yan clan dared not bear this crime. Unfortunately for them, Xinzi needed three things:
Scapegoats to make the demon's Yanzhou presence as understandable as possible.
A distraction that'd collect the attention of the Demon Slaying hall.
And if possible, an opportunity to harvest massive benefits.
Demons collecting souls and Evil Qi was just the norm. But without the backing of local forces, only a fool would dare to expose his presence on such a large scale. After all, the Demon Slaying hall would hunt them down relentlessly.
This also made the demon's "rampant actions" in the White Immortal sect and Thousand Roads mountain more understandable as, with the Yanzhou Hegemon to back him, he didn't have anything to fear.
Enjoy!