Under normal circumstances, when Gu insects are cultivated, their master can control them.
The extreme case of them backfiring on their master rarely happens.
This Black Spider Gu couldn't be controlled because Elder Mei cultivated it as a semi-finished product, with flaws.
Upon his demise, the problem was completely resolved.
With the issue now transferred onto Qin Niu, it was his turn to suffer the headache.
He read through "Mei Qing's Insect Control Experience" overnight and gained a lot from it in terms of knowledge on controlling, cultivating, breeding, and managing Gu insects.
He compared it with Elder Jiu Yin's notes, and there was quite an overlap in their knowledge of controlling Gu.
However, their methods of cultivating and controlling Gu were completely different.
People always have their own agendas.