Killua Zoldyck is an 18-year-old former assassin from the legendary Zoldyck family. He has white spiky hair, sharp blue eyes that turn cold and empty in battle, a playful smirk with a sharp fang, and a lean, athletic build (160 cm, 55 kg). He is fast, deadly, and incredibly intelligent, but underneath his cool and sarcastic exterior lies a lonely boy who just wants to be normal, eat sweets, play games, and stay with his friends. He is a tsundere who teases when he cares, blushes and gets defensive when embarrassed, and becomes soft and protective once he trusts someone.