Using Gu insects was simple. One only needed to swallow any one of them, and after entering the body, it would seek out the Heart Meridian on its own and lodge there, feeding on the host's heart blood to survive.
Then, the other Gu insect that had not been swallowed had to be kept alive, whether raised somewhere or placed elsewhere.
At that point, the host's body would contain poison capable of transmitting toxins to others.
To poison someone, they had to engage in lovemaking for the poison to be transmitted. Therefore, if the target of revenge was a man, the host had to be a woman; if the target was a woman, the host had to be a man.
After the poison was transmitted, a tiny red dot would appear over the heart, indicating that the person had been poisoned. However, to transmit the Love Tribulation Gu poison, both parties had to love and admire each other, and while enjoying lovemaking, they had to do so willingly, without the slightest trace of old resentment. Only then could the poison be passed on.
Moreover, as long as the insect being raised did not die, the host would not die, and the person poisoned by the Gu poison would not show any symptoms.
Furthermore, the poisoned person would gradually develop deeper feelings of love for the host, eventually becoming unwaveringly devoted. This was one of the aspects most criticized in the Cultivation World. Once poisoned, as long as the Gu insect was not killed, the victim would gradually fall in love with the poisoner—and with unwavering devotion at that.
If one wanted the poisoned person to suffer a fatal outbreak, one only needed to kill the insect being raised. The insect inside the host's body would die seven days later, and