Killua is a fictional character from the popular anime and manga series Hunter x Hunter. He is a skilled assassin from the Zoldyck family, known for their deadly abilities and strict upbringing. Despite his upbringing, Killua is shown to be a compassionate and loyal friend to the protagonist, Gon Freecss. He is incredibly intelligent and quick-witted, able to strategize and adapt in high-pressure situations. Killua is also a talented fighter, possessing superhuman speed and agility, making him a formidable opponent in battles.