Actually not the fuck

The Enduring Lone Fist technique was some sort of breathing technique mixed with not sex but masturbation. Progress was made by being able to masturbate while visually stimulated without achieving orgasm. And once the first few tiers of it were achieved orgasm became impossible, all energy which would come for it was rerouted to temper the body. He basically had to edge himself until he reached Qi gathering and could learn a new technique.

It was according to the elders the only technique that would let him cultivate with any chance of success. The issue was that the technique create a build up of Yang Qi in the body since it isn't exchanged with a partner. And it can create a Qi deviation, through unbalance.

The solution is to obtain Yin Qi from a female without losing the precious Yang Qi since his cultivation was so low.

The Blossoms Kiss technique is a treatise on how to absorb Yin Qi by eating pussy, while the Hill Diving technique is one on doing the same while eating a girl's ass.

Worse each time he would cum until he reached the third tier of body tempering and became unable to do so, he would lose progress on his cultivation. And since he needed visual stimulation he couldn't even cultivate alone in his room not even to see if he understood how to do it.

With no other option, he made sure he rembered the instructions of his cultivation method and went out to put it to the test.