Hayami sat foe a few hours, studying the book.
The Usong technique allowed injecting one's Qi through martial arts to another person. Once the target of the technique fails to resist it, the caster could control the other person's lust. The technique required touch. In combat it has temporary effect. It had higher chances of success if it was performed on sexual organs.
It was possible to make the technique permanent, if one performed it enough many times to attun ones Qi to target's Qi, making it indistinguishable, thus ommit all the target's defences. The technique was especially effective against normal people. The cultivators could defend against it.
Hayami understood the technique on basic level and could perform it with his hands... higher levels allowed usage of tongue, toes or penis... even one's savila or sperm could be used at some point...
