He comes from a family of notorious assassins and is trained in various forms of combat from a young age. Killua possesses incredible agility and reflexes, and has the ability to use electricity as a weapon. Despite his upbringing, he befriends the protagonist Gon Freecss and develops a strong sense of loyalty and friendship towards him. Killua is often torn between his assassin identity and his desire for a more peaceful and fulfilling life.