["There are 5 types of auxiliary applications: Nullification, Amplification, Regeneration, Infusion, and Omission.
"Nullification can be used in multiple different ways, but its primary use is to cancel out a manifestation of Qi. Or, in pill making, you can use your Qi to nullify or suppress the effects of one of the herbs.
"How do you do this, you may ask?"
"Well, it mostly boils down to the intent, power, and density you put into your attack or Qi. Affinity can also be important, but your understanding of Qi must have reached a sufficient level to pull this off. For example, let's say someone is throwing fireballs at you. You have to create an attack of equal power to hit those fireballs head-on, and you'd have nullified them.
