Initially, Killua is introduced as a character who seems similar to Gon; cheeky, cheerful, and full of mischievous ideas. He is also one of the most quick-thinking characters in the series. He is confident in his own abilities, often being humble about it. But when somebody compliments him, especially Gon, he gets easily embarrassed. Killua is also known for having a sweet tooth, as he spent almost 200 million Jenny on snacks when he was at the Heavens Arena. His favorite snack is chocolate, specifically the Chocolate Balls. However, his ruthlessness and aptitude in killing shows the other side of him — deadly, violent and bloodthirsty. Having been tortured since birth, Killua has been conditioned to possess extreme.