Biscuit (Bisky) introduces herself as a pro Hunter and reveals she was the master of their previous teacher, Wing. She decides to train the boys after realizing they lack the necessary discipline to survive the game.
In episode 63 of the 2011 anime, titled Gon and Killua officially begin their grueling training under Biscuit Krueger during the Greed Island arc . Summary of Key Events Hunter X Hunter 2011 Episode 63
Bisky effortlessly defeats Binolt , a serial killer stalking them, and turns him into a "training puppet". She gives Gon and Killua two weeks to defeat him or face her punishment. Biscuit (Bisky) introduces herself as a pro Hunter