Qinguang King used Yama's Spirit Soul as nourishment and the Karmic Mirror to convict all supernatural beings in the Netherworld, his aim was not only to eliminate Shen Yuan's aid but also to complete the process of sentencing all beings of the Netherworld.
Qinguang King then burned a second Yama's Spirit Soul, in such a manner engraving the Karmic Mirror itself into the rules of the Netherworld, thereby completing a coup and using the Karmic Mirror to govern the entire Netherworld rules.
The Netherworld, which had already been completely under Shen Yuan's control, began to tilt towards Qinguang King's hands because of this sentencing of all beings.
As long as the Netherworld's Karmic Mirror completed the governance of the Netherworld's rules, even if Shen Yuan were in charge of the Divinity Path, it would be of no use after all, the Divinity Path is just a tool to drive the Netherworld; the true source of everything is still the rules of the Netherworld itself.