After reaching the 200th floor, Gon and Killua run into Hisoka's barrier of Nen. They ask Wing to use the violent method for activating their Nen potential. As the deadline for registration draws near, they begin training in one of the four major principles of Nen, Ten.

After two months, Gon and Killua are finally allowed to practice Nen again. That's when Gido, Sadaso, and Riehlvelt appear before them and tell them to fight them in the arena. Gon and Killua refuse, but Killua finds Sadaso's behavior to be very suspicious.

Gon has fights against Gido and Riehlvelt coming up. He's still mad about what they did to Zushi. Gon is able to withstand Gido's attacks and overwhelm him in battle. This causes Hisoka to smile.