After Zushi's match with Killua, Wing intervenes before his disciple can reveal the true nature of Nen to the two, as he wasn't sure they were ready to learn it, going so far as to lie to them when it came to describing what Nen was.
However, when they advance to the 200th floor, where all the fighters are Nen users, he relents and agrees to teach them, in order to spare them the 'initiation' of the other fighters.
For the next several months, Wing taught the three the basics of Nen, namely Ten - the ability to control the aura flow, keeping it around the body, Zetsu -The ability to keep the aura sealed within the body, Ren-An advanced application of Ten, wherein more and more aura surrounds the body without drifting away.
He also explains the basics of Hatsu-wherein the users aura takes on a specific trait depending on their Nen type: Enhancer-Physically reinforcing the body with aura, Transmuter-Changing the quality of the aura (ie, like Hisoka's Bungee Gum) Emitter-Able to emit their aura from their body (ki blasts basically), Manipulator-able to manipulate others/objects with aura, Conjuror-manifesting a physical object through nen (like Kurapica) or Specialist-this is a rare type that has no real stats, though Conjurors and Manipulators may become Specialists later in life.
Wing himself admits to being an enhancer, as proven using the Shigen-ryu water divination method. He has exhibited the ability to envelop a page from a book with Nen, making it capable of slicing through a can of juice, and embedding itself in the wall. He also has the ability to use a special thread that breaks on contact with nen, which he used to ensure Gon kept his promise during his recovery period.
After Gon and Killua master the basics of Nen, (shortly after their battles at Heaven's Arena conclude) Wing announces that Gon has passed the secret final requirement for being a Hunter. He does however, somewhat fear their immense potential, though he assures Zushi he'll catch up eventually.
While a competent Teacher, Wing is not without his minor flaws. He has a habit of leaving his shirt half-tucked out, as well as turning up to foil any plans his 'students' may have to train without his permission.
He also has a nasty habit of not thinking ahead, such as when he ripped a page out of Zushi's book and used it to cut the boy's can of juice to demonstrate how dangerous Nen is.