After the long wait, Kyou and Eustace got what they deserve which is to learn nen. Arashi opened their aura nodes and together both Kyou and Eustace felt a sudden change in their body. Aura (オーラ) is the life energy produced by all living bodies vital for survival. Aura from all parts of the body has a tendency to flow together, producing one mass of energy. This happens without the individual's awareness, typically resulting in a slow leak of aura continually escaping the body.  If one were to lose their entire aura, it would be equivalent to using up all the energy keeping them alive, which would be fatal. The pores or points on the body from which aura flows out from are called "Aura Nodes" (精孔, しょうこう) shōkō). Controlling those nodes is the first step to being a user of Nen. Learning to use Nen is the final step in becoming a professional Hunter because most contracted jobs require the use of it as the minimum requirement. The technique has the ability to enhance the strength of physical attacks or objects depending on the quantity of aura employed and an individual's aura type, as well as allows for para-psychological abilities to exist in reality. Because one can craft just about any sort of psychic power through only using their mind, Nen is also a dangerous power unknown to the public at large. Arashi explains what is nen after both felt what it's like to have one.

Ten (点, Point): Focus the mind, reflect upon the self, and determine the goal.
Zetsu (舌, Tongue): Put it into words.
Ren (錬, Temper): Intensify your will.
Hatsu (発, Release): Put it to action

"Those are what you need to know, learn how to keep your nen inside your body otherwise you'll die and now for the final test, water divination." 

[img]http://vignette4.wikia.nocookie.net/hunterxhunter/images/8/8c/Learning_by_Water_Divination.png/revision/latest?cb=20130519203403[/img]

"I will not determine what your potentials will be as the divination will but I hope for the best. What abilities do you want?"

Kyou answered. "I want flames. Nonetheless. How about you Eustace?" She asked. Arashi said. "You'll find out soon enough once you're done with this." 

[@ThanatosDefiant]