Hunter x Hunter (2011) Episode 33: An x Empty x Threat
Episode 33 of 148 of Hunter x Hunter (2011), aired May 26, 2012, 25 minutes. Available with English subtitles and dub where released.
Episode summary
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.