It's the background music played when Illumi is ordering Killua to leave the hunter exam. It sounds like a piano mixed with some other instruments. Does anyone know what song it is?
The song playing around the time that illumi is talking to kilua at the timestamp 13:43 is 銀髪の少年 by Yoshihisa Hirano and is on the Hunter x Hunter 2011 Original Soundtrack as well as Spotify at the time of writing this
