Killua Zoldyck

**Killua Zoldyck** (キルア=ゾルディック, *Kirua Zorudikku*) is the third son of Silva and Kikyo Zoldyck and the heir of the Zoldyck Family, until he runs away from home and becomes a Hunter. He is the best friend of Gon Freecss, and is currently travelling with Alluka Zoldyck.

## Appearance

Killua has spiky silver hair, very pale skin and blue eyes. His eyes change shape depending on the mood that he's in, narrowing and sharpening when he goes into assassination mode. Killua is fairly lean at the start of the series, due to constant physical conditioning and torture training he received when he was young. As time passes, he becomes more muscular and toned. In the Nippon Animation anime adaptation, Killua's eye color is changed to green during the OVAs. He is also often seen holding a green skateboard (turned yellow in the 2011 series).

Killua typically wears baggy clothing, with his usual attire consisting of long-sleeved and dark-colored shirts. Most of his clothes have a turtleneck. Killua wears long, baggy shorts in the manga and Madhouse animated adaptation, but Nippon Animation's character design shortened them to reach above his knees. Killua also wears blue boots, recolored brown and black in the Nippon Animation adaptation.

As a child, Killua's hair is longer, almost cascading to his shoulders. He wore a hoodie with his trademark blue coloring, grey pants, and shoes.

## Personality

Initially, Killua is introduced as a character who appears similar to Gon: cheeky, cheerful, and full of mischievous ideas. However, contrasting Gon's politeness, Killua can be quite rude to others, mostly strangers and older people. He is most commonly known for having a sweet tooth; he loves everything sweet and spent almost 200 million Jenny on snacks when he was at the Heaven's Arena. His favorite snack is chocolate, specifically Chocolate Balls.

He is also one of the quickest-thinking characters, and often analyzes a situation with great ease and accuracy. In spite of his young age, his way of thinking, knowledge, and pragmatism give him the attitude of an adult. He is initially very confident about his own abilities, going as far as questioning Gon's capability during the Hunter Exam, and compares his strength with other people. As time passed, Killua became humble about it; but when somebody compliments him, especially Gon, he becomes easily embarrassed.
However, his ruthlessness and aptitude in killing shows the other side of him—deadly, violent, and bloodthirsty. Conflicting with Killua's predisposal to kill is his unyielding loyalty to his friends and natural kindness. He claims Gon was his first friend, and he grows progressively more attached to him as time passes. Killua often suffers immensely in his attempts to help his friends without a single complaint. He puts others before himself without being concerned about his own health or even his life.
Until recently, Killua's greatest flaw was his fear of those seemingly more powerful than him (one of whom being his elder brother, Illumi). Killua had been trained as an assassin by his brother to be extremely cautious and that he only engages in combat provided that victory is absolutely certain. This impeded him as a Hunter, as Biscuit stated more than once that victory is never certain, and that depending on the circumstances, a person has the potential to defeat a stronger opponent.[2]

Killua especially struggles with these dueling ideologies during the latter half of the series, as he begins to encounter stronger opponents. His brother's teachings remained firmly entrenched in his mind, to a point at which Biscuit prophesied that he would one day abandon Gon because of this. Finally, he had to face Biscuit's prophecy when he encountered a Chimera Ant while Gon (who could not use Nen at the time) was not far off and had no way to defend himself. At the last moment, Killua realized that Illumi had implanted a needle in his brain way back in the first Hunter Exam. This needle was responsible for forcing Killua to retreat and jailing himself in his comfort zone whenever any situation would potentially endanger his life. Upon extracting the needle, Killua was freed from this restraint and gained full control of his subconscious to make his own decision whether or not to flee whenever there is a need to fight stronger opponents.[3]

During the events of Greed Island, Killua has shown to be highly susceptible to gambling. Going as far to be willing to gamble with his life to get big reward in the slot machine and seem to show heavy gambling rush in his eyes causing Biscuit to neck chop him to make him stop.

A stark contrast to his best friend Gon, Killua is highly mature in both thinking and emotion in which he can keep his anger in check and maintain rationality better than Gon even facing terrified experience like the death of Kite while Gon gives in to his rage and loses his logical thinking.

## Equipment

**Skateboard:** The first time he faced the Hunter Exam, Killua brought a skateboard with him. It was able to bear the weight of five people and a wooden shelf without breaking, although it was damaged in the process. The skateboard is yellow with red wheels and a red arrow painted in the middle, reaching almost to the curved end of the deck (dark blue-green with a yellow arrow in the 1999 anime). The skateboard is also briefly seen in the beginning of Hunter × Hunter: The Last Mission.

**Yo-Yos:** After passing the Hunter Exam, Killua was given by Milluki two yo-yos made of a special metal alloy that he began using as a secret weapon. The yo-yos are extremely durable and heavy, each weighing 50 kilograms. Their reflective surface allows them to be used as mirrors to stealthily look behind a corner. Biscuit noted that they work well with Killua's ability to turn his aura into electricity.

## Abilities & Powers

Killua has all the benefits granted by his status as a Hunter. Furthermore, as a member of the Zoldyck Family, he has vast wealth at his disposal, although he needs his father's or his grandfather's permission to use them. His family name alone is enough to scare the ones that know what it is associated to. Killua has been trained since birth to become a human weapon, and is recognized by his family to be the most talented assassin in the entire history of the Zoldycks.[29]When he took the Hunter Exam the first time, he was the fourth most powerful applicant (after Gittarackur, and, by his own admission, Hisoka and Hanzo), and the one that Single Star Hunter Menchi believed would pass. Up until the Hunter Exam, he did not hesitate a second to kill, but after meeting Gon, this tendency subsided; still, he is not afraid to resort to extreme means when circumstances demand it. Like his friend Gon, Killua has an astounding natural talent that enables him to learn at a fast rate and allegedly ad infinitum, a characteristic that piqued Hisoka's interest. His potential extends to Nen as well, as noted by Wing and Bisky. Although he primarily fights with his bare hands, Killua is able to use any kind of weapons, but the only one he employs consistently are his custom-made yo-yos. When he tried to prevent the selection, he was so confident in his strength that he claimed that tanks and fighter jets would be useless against him.

His training endowed him with near immunity to poison, high tolerance to electricity, great agility and physical strength, advanced armed and unarmed combat and stealth techniques, which he acquired at a very young age. His intellect and exceptional analytical skills are equally remarkable, and it is often through strategy that he can defeat opponents who are stronger or more experienced than him. He is also able to walk without making a sound and sleep with a larger part of his brain awake than normal, so he can avoid attacks even in his sleep, even if they come from an armed, albeit weaker, fellow Hunter. After leaving Greed Island, due to his prowess in Nen, Killua became able to blend with nature more easily, which allowed him to find multiple new species of animals at a rate that astounded Kite's companions.[85]

Killua's main weakness used to be an inferiority complex that paralyzed him with fear and prevented him from fighting opponents that could pose a threat to him, even if their overall strength was lower than his own. Although it was originally believed to be a product of his training, it is later revealed that it was actually due to a Nen-imbued needle that Illumi had implanted in his brain. Its removal caused Killua to snap free of his brother's conditioning, thus regaining the full control of his mental capabilities in battle. This also had the effect of making his overall movements better, increasing his speed.

**Preternatural Perception:** Killua managed to detect Meleoron's presence in spite of the latter specializing in erasing it.

**Enhanced Strength:** Killua has displayed his strength on several occasions. Before he learned Nen, he was able to open a 16-ton gate[26] and after he learned Nen, he opened the 64-ton gate.[127] He can also easily lift up boulders several times his own size and cleave through massive trees with a single strike.

**Immense Speed and Reflexes:** Killua is considered to be one of the fastest characters in the series. Even without resorting to Nen, Killua is tremendously fast. He can move fast enough that his opponents may lose sight of him, and kill a target without them realizing until the fatal blow has been dealt. When he retried the Hunter Exam, he knocked out more than one hundred of applicants in a matter of minutes.[63] His speed was on par with Gon's when he was introduced, but following the removal of Illumi's needle, Killua became able to control his movements more adept, thus growing faster. A perfect comparison between his previous and current speed is given in his fights against Rammot: while in their first confrontation the Chimera Ant managed to overpower both him and Gon through sheer strength and speed, in the second Killua ripped his head off before Rammot even realized that his opponent had moved at all. His reactions are also first-class: Killua can react to the slightest amount of danger at once, even bullets fired at near point-blank range.[143]

**Immense Agility:** Killua's mobility allows him to attack from every position, move in the enemy's blind spot, and fight on any kind of terrain. In terms of defense, Killua takes full advantage of his agility to fall back quickly, dodge the enemy's attacks and react immediately after being hit. He has an excellent sense of balance, as seen when he was shown standing with nonchalance on the back of a horse,[144] and good coordination. He managed to dispatch a small squadron of Chimera Ants that had drawn him in the treetops and surrounded him in a few seconds, not only avoiding their attacks, but also turning them against his assailants.[101]

**Enhanced Stamina:** Killua is indefatigable, both physically and mentally. He can withstand wearing battles, training sessions and runs. Not even thirty hours of continuous traveling NGL by foot and battling the armed forces could wear him down.[100]

**Enhanced Durability:** Killua took no damage from being kicked in the belly by Imori. He also stated that a blow to the neck that Hanzo used to knock out Gon would only leave him stunned. Even being electrocuted with 1,000,000 volts of electricity can only cause him to feel pain. Ikalgo's bullets, while packing enough power to send Killua flying a few meters, could only pierce less than an inch of muscle.

**Enhanced Endurance:** Killua can bear very intense physical pain without his physical or mental abilities being impaired. He fell asleep (or pretended to) while his brother Milluki was whipping him, and did not react when the latter burned him with a cigar. He can also dislodge his joints without seeming to suffer any drawback. A better example is given during his confrontation with the Ortho Siblings, in which he had his body punctured by several darts and still managed to make calculations and prepare a strategy, even coming up with an idea for a new ability.

* **Resistance to Electricity:** As a child, Killua was trained to endure large amounts of electricity. His older brother Milluki often electrocuted him for training and punishment.[29] As a result, he is able to withstand high-voltage electrical currents while retaining his full mental and physical faculties, even when suffering shocks capable of stunning Sub, a superior Nen user at the time, as well as paralyzing and hurting the powerful Menthuthuyoupi. However, he stated that even though he has strong resistance against electricity, he still feels the pain.[38] Due to this, Killua was able to develop electricity-oriented Hatsu techniques.

**Immense Poison Resistance:** Due to his assassin training, Killua became resistant to a great number of poisons, toxins and chemicals. He first displayed this ability when he drank five cans of Tonpa's juice during the Hunter Exam without experiencing any side effects, despite the beverage containing a laxative that, in that dose, should have completely dehydrated him. When he was stung by Mosquito, he revealed that her toxin had absolutely no effect on his body.[145]

**Muscle and Joint Control:** Killua can dislodge his joints at will in less than a second, an ability that enables him to escape from most ties. An instance is given when he dislodged his shoulders, elbows, wrists and fingers to free himself from Machi's strings.

* **Claws:** One of the several assassination arts passed down to Killua through his family consists in adjusting the anatomy of his hand; his fingernails turn into claws that are sharper than knives, with which Killua can sever a limb, a head or even rip out an heart with frightening ease.[17][146]

**Healing Factor:** Killua can recover from injury faster than normal, as demonstrated when the multiple wounds inflicted to him by the Ortho siblings completely healed in only a few days.

**Genius-Level Intellect:** Killua's intelligence surpasses that of a normal boy his age by far. He is knowledgeable about a wide variety of topics, endowed with prodigious intuition and analytical skills. His abilities in deductive reasoning are comparable to those regarded as the smartest in the Hunter × Hunter world within the characters shown so far. Though not always being at the top of the game as he still gets out-witted from time to time, but nonetheless it is still extremely remarkable for his age. He can also bear severe mental strain and still think clearly, to the point that even Hunters with more experience than him rely on and take notes from his predictions before making a move; and he can come up with hypotheses and conclusions that are well beyond ordinary thinking. To match all of these impressive intellectual capacities, Killua is also an extremely quick thinker, who is capable of adapting to completely unpredictable and absurd scenarios.

**Master Strategist:** Killua is capable of devising complex tactics, run accurate simulations and evaluate the success rate of each of them, even in the middle of a fight. Biscuit, Morel, and Knuckle all accepted his strategies as the best. He can not only predict the general going of an operation, but also the actions of each individual, even if he has never met them.

**Master Hand to Hand Combatant:** In spite of his young age, Killua is one of the best male fighters in the series. He is capable of fighting on even ground with foes that are physically stronger than him or have better control over their aura. His fighting style, which is extremely versatile, aims at dealing the maximum amount of damage in the shortest time possible, striking critical points and making ample use of lightning-fast submission holds to incapacitate or kill the opponent. He can precisely knock a person out by touching a sensitive spot on their neck.[63] Killua is particularly skilled at finding patterns in the fighting style of his adversary and at figuring out their weak spots, and at using them to exploit or create an opening with which end the confrontation. It is very rare for him to resort to combos, both because his training has led him to favor sneak attacks and careful planning and because one strike from him very often results in the death of his target. Due to the Zoldyck philosophy of never putting their lives at risk while fighting, he was also taught a wide array of defensive and escape tactics, a trait that was exacerbated while Illumi was conditioning him. Following the removal of his brother’s needle he began to take more risks when fighting, which, far from weakening him, had the effect of making his overall movements more secure and, thus, faster and more precise. He also received basic training in Shingen-ryū *Kung-Fu*.

* **Assassin Mode:** When employing his assassination techniques, Killua enters a state of mind that helps him channel his strength and concentration for the sole purpose of slaying his opponent. He compares the process to flipping a switch.

* **The Snake Awakens** (蛇活 (だかつ), *Dakatsu*)**:** Killua whips his arms with incredible fluidity and speed, cleaving anything that comes in contact with them.[145]

**Master Weapon Specialist:** Although he prefers to fight with only his bare hands, Killua is capable of turning any object into a lethal weapon, even if he has no familiarity with it. He won Bopobo’s challenge by drenching him in liquor and setting it afire, and killed multiple soldier Chimera Ants with the arms they wielded. Killua is also adept at using projectile-like weapons, although he has never employed any in combat. His weapon of choice are two yo-yos weighing 50 kilograms each, which he can wield with great dexterity, that amazes pro Hunter Shoot McMahon. He can use them as long-ranged weapons, to ensnare the target, grab distant objects, as a grapple, or swing them around himself to counter incoming attacks. His aura can also be channeled through them to shock a target from a distance. Killua is reluctant to use them in battle if he is unable to prevent the information from being leaked to other potential opponents, preferring to resort to his raw physical abilities and combat skills in order for his opponent to know as little about him as possible.

**Master of Stealth:** Killua is very proficient in hiding, spying and infiltration. Melody, a Hunter renowned for her hearing, commented that she could hardly hear Killua's footsteps even when he was running alongside her.[147]

* **Shadow Step** (暗歩 (あんぽ), *Anpo*)**:** Due to his training, Killua has learned how to walk and run without making a sound.

* **Rhythm Echo** (肢曲 (しきょく), *Shikyoku*)**:** An assassination art, the Rhythm Echo is a motion that creates an afterimage of the body through a varying cadence of steps. There is a total absence of noise during the movement, and multiple phantoms appear. It utilizes the Shadow Step technique; In the Nippon Animation adaptation of the anime, Rhythm Echo is changed into an ability that allows Killua to disappear into darkness. According to Netero, it is the advanced version of the "Silent Gaits" technique.

* **Expert in Tailing:** Killua tailed Nobunaga and Machi around a town with the two of them failing to spot him (although they clearly sensed his presence).[4]

**Masterful Skater:** Killua is extremely dexterous with his skateboard, performing acrobatic tricks with ease. He has also been shown to use his skateboard to kill a Great Stamp.

**Masterful Darts Player:** Killua mastered the game when he was six (or seven), with a count of 1440 points. This skill came in handy against the Ortho siblings, when he recognized the rules the brother was playing with.

### Nen

As a Transmuter, Killua's most efficient in changing the properties and shape of his aura. Just like Gon's, Killua's talent is said to be absolutely astounding, found only in one out of ten million people.[39] Thanks to Biscuit's training he has honed his skills in at least two Nen types other than his own, namely Enhancement and Conjuration.[148] He has also mastered the four basic techniques and at least five of the advanced ones (the exceptions being possibly In and En, although he is able to extend his Ren to a radius of 57 cm to sense incoming attacks).[143] He performed Ten successfully with next to no instructions, a feat which Wing described as both "amazing" and "terrifying",[34] and learned Gyo in only one night.[36]He is able to maintain Ren for three hours outside of combat without the slightest difficulty.[149] His Zetsu earned him the praise of the Phantom Troupe, although they were able to sense him.[4] He can form Ko in an instant, as shown when he used it to knock Gon out while the latter was going to fight Neferpitou.[88] While Gon can release a bigger amount of aura, Killua is generally hailed as the one with the best control, to the point in Greed Island he was already capable of distributing his aura with a margin of error lower than 1%, which caused Biscuit to comment that she reached his degree of mastery only in her late twenties. In spite of his lack of experience, he can measure with accuracy how much aura he should employ and in which area in a split second, relying solely on the instinctive knowledge granted by his fearsome potential.[75] He easily got ahead of Gon during their training on Greed Island,[150] overcoming his inexperience with sheer insight.[75]

Killua developed a series of Nen abilities in which he alters the properties of his aura to make it similar to electricity. This was inspired and made possible by the years of electric shocks he received as a child, both as training against torture and as punishment from his older brother Milluki. Biscuit was very impressed that he could create such a complex Nen ability at his age.[148] He can shock the opponent either through physical contact or while keeping his distance, channeling his aura through his yo-yos[79] or throwing it in the form of a lightning strike.[116] Although most Nen users receive no damage from the electricity itself, they are still hurt and paralyzed for a few instants.[79] The peak of Killua's Nen abilities are two Hatsu collectively referred to as **Godspeed ( *Kanmuru*)**, both of which use Killua's electric aura to vastly enhance his speed by allowing him to transcend the limits of his physical potential: Whirlwind makes his movements automatic, while Speed of Lightning allows him to remain in control his body.[116] Regardless of which core function he employs, he can regulate the discharge of electricity outside of his body, making it so an ally touching him will only feel a mild stinging sensation,[133] whereas an enemy being struck by one of his blows will be painfully electrocuted[116] and even suffer burns if unprotected.[122] Both applications can also be used to carry others, both to displace them[133] and to protect them from enemy attacks.[122]

In order to generate electric aura, Killua needs to "charge" himself by letting electricity run through his body,[151] such as by tasering himself[60] or holding onto a plug,[117] although, by his own admission, it is not very potent and he runs out of it rather quickly.[152] Another inconvenience is that Killua is not aware of exactly how much electric aura he produces, which can result in him depleting his reserves unexpectedly.[116]

In the second film and the 2011 anime respectively, Killua was able to use the electric aura to activate simple machines or burn sturdy objects, such as Rhino's exoskeleton, to make them frailer and subsequently break them.

## Quotes

* *"Gon, let's get in front. Yeah, and it'll get us **away** from Hisoka. He's killed, and wants to kill **again**. The fog will make a great cover. You're wondering how I know. Fact is, I'm like him. I can **smell** it in him."*[154]
* (To Kurapika) *"If that's how you feel, **I'll** kill him for you. It's no **big deal**, y'know."*[155]
* (To Amori) *"Keep still. My nails are **razor sharp**."*[20]
* (To Illumi) *"I'm so tired of killing, I just want to be a kid. Hanging out, doing stuff with Gon. That's it."*[25]
* (To Sadaso) *"Move, and you die. Use Nen, or utter one word, and you die. Now close you eyes... You see what happens when you break promises? Open your eyes again and look at me in the mirror. Listen. Don't you **ever** show your scummy face to us ever again. This is a promise you **will** keep."*[36]
* (To Riehlvelt) *"Electricity won't work on me. But that only means I can **tolerate** it. It still hurts. And sure it doesn't make me happy."*[38]
* "*I've had to play life-or-death games of "shadow" since I was three. I would feel their heart skip a beat!! I would never be dumb enough to miss it!!"*[4]
* *"Gon, I'm the one. I'm glad to have you as a friend."*[156]
* *"We were complacent. Too confident of our powers. Both of us combined were worth less than a one-armed Kite. That was his assessment... That's the reality. If Kite was by himself, this wouldn't have happened. We were fools."*[88]
* (To Chairman Netero, Morel, and Knov) *"One of them could use Nen. His aura was creepy more than anyone I've ever met. More than my brother or Hisoka. Now that I've learned Nen, I can tell. You guys are powerful, too. And still, I don't think you can take him."*[89]
* *"Gon, you are light itself. Sometimes you're too bright and I can't look at you... But can I still stay by your side...?"*[89]
* (To Ikalgo) *"Because I thought you were cool. If we'd met another way, maybe we could've even been friends."*[102]
* (To Menthuthuyoupi) *"Sorry but I'm a little ticked off right now. So I'm just gonna take it out on you."*[116]
* (To Palm) *"Gon's suffering right now!!! Someone who meant a lot to him was ruthlessly altered!! Even his **mind** was changed. As we speak, Gon's facing against the person responsible!! If you up without warning, looking like that, he won't be able to hold it together. So you have to promise to call him by his name first!! That's my one condition! Let him know you're okay. He was so worried about you, up to the minute we came in here. Give him some peace of mind. Please. Put his mind at ease. Only you, Palm, can do that right now. Nobody else can reach him. Not me. I can't help him anymore!!"*[119]
* (To Shaiapouf) *"I don't know what you're deal is, but I **do** know that you piss me off."*[122]
* (To Palm) *"Don't worry. I won't say it again. After all, we're friends. I don't need to thank my pals every time."*[123]
* (To Silva) *"If I leave my friend to die, isn't that the same thing as betraying him?"*[127]
* (To Illumi) *"Bring it on. I'll show you what I can do!!"*[131]
* (To Illumi) *"The one who's cursed is the one making wishes!!"*[135]

## TMNT X Pokemon

As an assassin, he teams up with Mine and Lubbock during missions.

## Trivia

* The Official Hunter × Hunter Character and World Databook spelled Killua's full name as "**Killua Zaoldyeck**".[157]
* Out of the four main protagonists, Killua is the youngest; during the first phase of the Hunter Exam, he confirms that his age is almost 12, just like Gon.[7] Gon's birthday is May 5, while Killua's birthday is July 7, making Killua younger than Gon.
* Out of the main characters Killua is the only one with siblings.
* Killua is the 3rd Transmuter in the Zoldyck family, after Zeno and Silva. All have silver hair as well, a trait found in all known Transmuters in the Zoldyck family.
* Of the four main protagonists, Killua is the only one to have failed a Hunter Exam.
* Killua is reported to be four centimeters (about one inch) taller than Gon, but the two are often seen being the same height.
* His favorite food are ChocoRobo-kun chocolate balls.
* He is nicknamed *Kil* or *Killu* by his family. However, neither the Zoldyck's employees nor Gon and his friends use this name.
* According to the "Hunter × Hunter Manual" section found in the Yu ☆ Yu ☆ Hakusho official character book (Shueisha Jump remix), Killua's stats are:

### Anime and Manga Differences

* Killua's eye color shifted in the 1999 series; though initially dark blue, his irises became green in the OVA series. In 2011 series, his eyes are back to dark blue.
* In the 2011 anime, instead of destroying Johness' heart, Killua gives it back to Johness after he faints and dies.
* He once stated that he does not know how to write letters, but he had written a "death notice, Zoldyck style" before.
* He hates red peppers. At Gon's house, Mito forced Killua to eat them, but he spat them out.
* In the 1999 series, Killua enjoys exploring cockpits and drinking tea.
* Still in the 1999 series, Killua was slapped two times by two different women: Mito Freecss and Biscuit Krueger.
* In the 1999 anime, he watched a porn movie in a hotel in Yorknew City.
* The 2011 series added some scenes where Killua and Canary first met as children. He also tried to make friends with Canary, but he never tried to offer her an animal skull.

### Intertextuality and References

* Killua is occasionally drawn with catlike features (paws, ears, mouth) in humorous situations, much like Botan of *YuYu Hakusho* (a previous work by the same *mangaka*) was.
* Hiei, one of the main characters from *YuYu Hakusho*, bears some similarities to Killua:
	+ Both of them have gone through a tragic childhood, killing people at a young age and being submitted to torture.
	+ Just as Hiei can conjure up fire and manipulate it, so does Killua replicate the characteristics of electricity with his aura. This ability was based on the immunity Killua had developed during a long childhood of electrical torture.
	+ Both are extremely fast.
	+ Both tend to kill their opponents in the most brutal ways and lack remorse when doing so.
	+ Hiei was ranked on first place for most popular character in the *YuYu Hakusho* manga, Killua had also won first place in the Hunter × Hunter popularity votes.
	+ Just like how Hiei is the last person Yusuke meets out of the main team, Killua is the last person on the main team that Gon meets.
	+ Both can use sharp objects as weapons, Hiei his sword and Killua his fingernails, but are also exceptional hand-to-hand combatants.
	+ Just like Hiei has black spiky hair and same colored clothing, Killua has white spiky hair and same colored clothing.
	+ One of the differences between Killua and Hiei is that he actually smiles in contrast to his *YuYu Hakusho*counterpart who is never seen smiling.
	+ Another difference is that Killua quickly befriends with Gon on their first meeting, unlike Hiei and Yusuke who start off as enemies.
* Killua's yo-yo's may have been derived from Rinku, a secondary character of Togashi's other series *YuYu Hakusho*.
* The Japanese name of Killua's Thunderbolt ability, *Narukami*, comes from the famous *kabuki* play *Narukami Fudô Kitayama Zakura*, in which the character Narukami transforms into a thunder god at the end of the fourth act.
* Godspeed closely resembles the real-life martial art concept of *Mushin* (無心, "Empty Mind"), a mental state that highly-trained martial artists are said to be capable of entering during combat. It is essentially a moment where their body reacts without the need of having any specific intentions or plans in mind, having refined their instincts and intuition to a level where they can respond to any threat without the need for thought.
* There is a castle in Ireland named Killua Castle.

### Miscellaneous

* Killua's name in Japanese is written as "*Kirua*" in *katakana*. It combines the Japanese transliterations of the English words "kill" (*kiru*) and "killer" (*kira*).
* Killua ranked first in all of the three character popularity polls that have been conducted so far by Weekly Shonen Jump.
	+ Fans stated that his changing moods gave him a lot of points and Killua looks strong. Fans also wanted Killua as their little brother.
* In the French version of Hunter × Hunter, Killua is nicknamed "Lukia" by Leorio.
* Killua's birthday falls on *Tanabata*, a Japanese festival holiday centering around a folklore tale of star-crossed lovers. Killua and the character of Orihime share some similarities, and the beginning of the *Tanabata* myth also shares some themes with the beginning of Killua's character arc:
	+ Both Killua and Orihime are employed by their fathers.
	+ Both Killua and Orihime are unhappy in their lives and wish for connections with others that their work prevents.
	+ Both Killua and Orihime eventually abandon their work entirely after meeting another person, which displeases their fathers.
	+ Both Silva and Orihime's father allow their children to pursue their important bond, but expect that their children will return to their roles in time.
	+ Additionally, the number of the month and day of Killua's birthday are the same: he shares this characteristic with the other three protagonists and Hisoka.