Wing is somewhat absent-minded about his appearance and has a fairly modest demeanor. However, he is more than he appears. He is an assistant master of Shingen-ryu kung-fu, a former student of Biscuit Krueger and a skilled nen user. He is an enhancer whose nen ability has not been revealed.
Plot
Heavens Arena
Gon and Killua first encounter Wing and his student Zushi when they are competing at the Celestial Tower. During Killua's match against Zushi, he noticed several anomalies that he couldn't explain. While Killua was obviously more skilled and physically stronger, he couldn't seem to knockout Zushi no matter what. Secondly, during the match, Zushi used a technique which seemed to impart a feeling of extreme danger and dread even though he didn't appear to be doing anything significant. This technique appeared to be the same as the one used by Illumi and Hisoka. Killua later overhears Zushi and Wing talking about Ren so he and Gon ask Wing to teach them about it. At first, Wing deceives them about Nen and its purpose because he feels unwilling to teach
Wing Explains Nen.
Nen to people who are not his students.He later reconsiders training them so he gently awakens Gon's and Killua's Nen points and takes training them seriously so they can prove to be able to reach the 200th floor where everyone uses Nen. He punishes Gon for playing around during his match and restricting him from seeing Hisoka's match and using Nen for two months. After the pair finishes learning the basics, he congratulates them as they pass the secret part of the Hunter's Exam, revealing he is their Examiner and that the other Hunter examinees that passed are learning Nen as well.
Greed Island Arc
His next appearance is during the Greed Island Arc, when Gon calls him for advice in developing a Hatsu ability that he can show to Tsezuguerra in order to be a participant in the video game. Wing and Zushi were still at the Heaven's Arena at the time.
New Hunter Chairman Election Arc
We later see Wing at the chairman election.