Killua Zoldyck from Hunter × Hunter has spiky silver-white hair, very pale skin, and striking blue eyes that narrow into sharp, cat-like shapes when he enters assassination mode. He has a lean, athletic build from harsh childhood training and typically wears baggy, casual clothes like long-sleeved dark turtlenecks. Physical Traits Hair: Spiky, silver-white locks (longer and shoulder-length in early childhood flashbacks).Eyes: Large bright blue eyes that turn sharp and menacing during battle or killer intent. Build: Slender and lean early on, growing more toned and muscular during later arcs like the Chimera Ant arc. Clothing and Style Main Outfit: Usually wears a dark, long-sleeved high-necked shirt with a lighter short-sleeved shirt layered on top, paired with baggy shorts and boots. Accessories: Famous for carrying a green skateboard during the early Hunter Exam episodes Killua Zoldyck is a complex, sharp, and loyal boy. Raised as an elite assassin, he swings between a playful, childlike demeanor and a cold, lethal bloodlust. His core arc revolves around rejecting his family's brutal legacy to find genuine friendship and his own identity. Core Traits Playful & Cheeky: Enjoys teasing others, has a massive sweet tooth (especially for chocolate), and acts like a normal boy when relaxed. Brilliant & Analytical: Possesses exceptional tactical intelligence, reading situations and opponents with cold, clinical precision. Deadly & Ruthless: Can switch instantly into an "assassin mode" where he detaches his emotions to kill without hesitation. Psychological Struggles Low Self-Worth: Because of severe conditioning and torture by his family, he views his own pain as normal but treats Gon's life as infinitely precious. Internal Fear: Plagued by the psychological conditioning of his brother Illumi—symbolized by a subconscious Nen needle—which initially forces him to run away from uncertain fights. Deep Loyalty: Devotes himself entirely to Gon, seeing him as his very first true friend and a shining source of light. Killua Zoldyck was born into the infamous Zoldyck family of elite assassins residing on Kukuroo Mountain. Raised as the heir, he endured severe physical torture and conditioning from a toddler to build immunity to electricity and poisons. Seeking a normal life, he rebelled, ran away, and joined the Hunter Exam. Early Training and Abuse Torture conditioning: Subjected to high-voltage electric shocks and heavy poisons from infancy so his body would adapt.Prodigy status: Recognized as the most talented heir in the family's history, reaching the 200th floor of Heaven's Arena by age six. Psychological control: His older brother Illumi planted a Nen needle in Killua's brain. This forced him to retreat from fights against unknown or superior foes to preserve the bloodline. Rebellion and Leaving Home Breaking away: Exhausted by endless killing and the pressure to inherit the business, Killua stabbed his mother and slashed his brother Milluki before running away. The Hunter Exam: Entered the 287th Hunter Exam purely out of boredom, where he met Gon Freecss, forming a life-changing friendship. Breaking the Mental Chain Needle removal: During the Chimera Ant arc, facing a deadly situation, Killua realized Illumi's control was holding him back. He pulled the needle from his head, fully regaining his autonomy and courage. Killua Zoldyck is a Transmuter. He turns his aura into electricity, an ability he developed thanks to the painful electric shocks from his childhood assassin training. His ultimate power is Godspeed (Kanmuru), which splits into two main sub-abilities. Electric Aura and Thunderbolts Lightning Palm: Killua shocks an enemy by touching them with his hands.Thunderbolt (Izutsuchi): He throws a bolt of lightning from his hands to strike an enemy from afar. Recharging: His main weakness is that he stores a limited charge and must physically plug into a wall socket or grab a live wire to recharge. Godspeed Whirlwind: His aura senses threats and moves his body automatically to dodge and counter-attack faster than normal nerve signals allow. Speed of Lightning: He keeps conscious control of his movements while wrapping his body in electricity to run and dash at super speeds.