Hunter x Hunter Episode 28: Nen x and x Nen

Wing teaches Gon, Killua, and Zushi in his room, explaining four main principles: Ten, Zetsu, Ren, and Hatsu, which he calls Focus, Express, Temper, and Act. Wing tells Killua he will think about killing him. He demonstrates Ten by focusing his body, Zetsu by saying "I'll kill you," and Ren by emitting a strong aura of intent to kill. Killua, feeling the pressure, jumps back and clings to the ceiling corner. Wing advises them to train with Zushi and master Ten, but Killua suggests they leave.

Killua tells Gon that Wing lied to them. He admits Wing's explanation made sense and his strength is real, but it doesn't explain how Zushi withstood Killua's last attack with sheer willpower. Back in the room, Wing notices Zushi's Ten is unstable. Zushi asks why Wing lied to Gon and Killua. Wing explains that the "Nen" he described is important for learning the real Nen, and he cannot teach the real Nen to those who are not his students. Wing tears a page from a book, uses a technique to sharpen it, and easily slices a soda can in half from across the room. Zushi is shocked, and Wing tells him that anyone can use Nen with enough effort, so one must be cautious when teaching it.

After clearing the 190th floor, Gon and Killua advance to the 200th floor. They are stopped by a strong, murderous aura that prevents them from moving forward. They barely push through it as a receptionist appears, stating they need to register before midnight. A man named Hisoka appears behind them and the receptionist, warning them they are not ready. He uses a powerful technique to prevent Gon and Killua from progressing. Wing then appears behind them to stop them from hurting themselves and offers to teach them the real Nen. Before they leave, the receptionist informs Killua that if he doesn't register by the deadline, he will never be able to register again, as he failed to register once before when he was younger. In Wing's room, Gon and Killua are finally taught the real Nen. Wing tells them they must learn Nen to protect themselves from other users of this power, explaining that they must use Ten for defense. To demonstrate how destructive this power can be, he places his hand against a wall and damages it, leaving Gon and Killua stunned.