Hunter x Hunter (2011) - episode 85 - 22 Jun, 2013

As the Chimera Ants are reunited to unlock the power of Nen in their bodies, Neferpitou senses Kite approaching and leaves to confront him. Realizing that the enemy is too powerful for them, Kite warns Gon and Killua to flee, but Gon is taken by rage upon seeing Kite's arm being severed by Neferpitou. Killua is forced to knock Gon out and escape carrying him. After escaping the NGL, with Gon still unconscious, Killua is approached by Chairman Netero, who has been sent there to wipe out the Chimera Ants with the help of two other Pro Hunters, Morel and Knov. (Source: Wikipedia) Chimera Ant arc: (10/61)