Nen Techniques: Mastery and Continued Cultivation
Mastery of Nen:
Nen Mastery is, perhaps, misleading. There is no pinnacle to reach because it is a constant refinement of self. Your life force, or aura, shunted into reality and shaped by willpower. Nen Mastery is expressed, however, as an individual's Hatsu.
Hatsu is every Nen users personal expression of self. It is their defining measure of power and their willpower given form. Hatsu is what is generally used after a certain level of proficiency in the basic and advanced Nen techniques is achieved. Further refinement of Nen is usually achieved by advancing Hatsu.
Pure manipulation of Nen is hard because of its vibrancy. Nen is life force and it is alive, this comes with certain caveats one must observe. At its most basic, Nen is an energy meant to mutate the body into a higher state of being. Constant and complete immersion in one's Nen for long periods of time allow for higher levels of physical ability even without training. Isaac Netero, as a specific example, is a Nen user that is said to have trained for ten years at the age of forty to express his gratitude for martial arts. This resulted in immense strength and concentration of aura and is believed to be the source of his powerful 100-Type Guanyin Bodhisattva technique.
In conclusion, a Mastery of Nen is achieved only when one believes they have nothing left to master.
クリエイターの想い 
Lokordome
Lokordome I will take credit for this explanation of things. I'm going very Eastern Cultivation with my explanation of Nen because I feel that it best expresses what I want. If you guys disagree with what I say or have a better, more creative, idea then comment and I'll try to respond.