Due to the lack of a medium, even Wang Zijia, who possessed a world-shaking curse technique, was helpless, like a skilled woman without rice to cook. This was a core limitation of curse techniques.
As for the other path, divination...
To divine and pinpoint a God Monarch when he didn't even know any real information, not even whether the name was real or not... it was nothing short of daft, something only someone who hasn't grasped reality would consider. He wasn't that delirious yet!
The Dao of Divination was one of the most significant schools in Cultivation. Normal people would always be prepared against it, and the cultivation world even sold various anti-divination methods, tools, and talismans all the time.
One could almost say they were common commodities deep into custom-made premium and luxury market.
Not to mention these heterodox demons!
You should know, witchcraft, poison, Gu, and curses, were all niche schools in the heterodox Dao.