Killua has long, reddish hair. His hair slowly turns to yellow at the tips, from the sun. Around his waist, he has four thick leather belts, each with lots of little pouches full of different tools to fight with. He wears light leather armor with an iron forehead protector.
Killua's personality isn't really something that can be described by one word. With him being such an complex person it is very hard for anyone to ever really "define" him.
His dominant traits are his confidence and his utter fearlessness. Despite his cockiness, he appears to be a calm person. He is also shown to fall into a state of extreme rage when insulted. Other benders point out that Killua tends to be naive, due to him acting without understanding the situation. Contrary to what people say, he is extremely understanding and prefers to act once he has analyzed the situation. He has an obsession with training, as for he wants to become one of the strongest fire benders to live.
Killua is expertly manipulative and prone to think several steps ahead of those around him, giving him a remarkable talent for making subordinates act exactly as he wishes despite appearing not to have had a hand in their decisions, and has been shown some aspects of greedy and selfish desires. He has a strange habit of making singing tones while talking, especially when he is nervous.
Killua was born in the Fire Nation in the year 161 AG. He came from a noble family known for their fire bending abilities. His parents were both residents of the Fire Nation, who encouraged Killua to become a powerful bender. At the young age of 5, his father would spend countless hours alongside Killua training. He began fire bending at the age of 6, and was taught to bend without relying on hate. His ability began to develop significantly under his Father's tutelage.
At the age of 9, he was an extremely skilled bender for his age. After he got back from school, and completed his homework, he would spend countless hours perfecting his technique. He excelled at learning and memorizing fighting patterns. Killua's motivation and desire was to become the most powerful bender of all time.
Killuas parents even went so far to hire a full time trainer for Killua. They were semi-obsessed with seeing Killua become a hero of the Rebellion. They treated him like a dog, who had to listen to all their commands. He didn't mind though, it only encouraged him to prove to his parents that he had the potential to do great things. He began pi
4 years later, he turned 13. During this time, his family was moving to Republic City for seemingly unknown reasons. This enraged Killua, as he felt it was his only home. Surprisingly, he settled in quickly in his new lifestyle. His parents allowed him a lot of freedom, which he took advantage of. He began competing in underground pro-bending matches. He had never felt so alive, fighting an intense match where his opponents would have no mercy. It would make his fingers twinkle, and his stomach have butterflies. He had a sadistic view in fighting, where he felt pleasure by defeating others.
- Killua was inspired by Adlet Mayer.