Hunter x Hunter — Episode 33: An x Empty x Threat!

You are watching the episode An x Empty x Threat! 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.