Illumi Zoldyck

"You can't defeat me. The answer's already there. Don't fight with opponents you cannot defeat."

- Illumi Zoldyck, to Killua Illumi Zoldyck (イルミ＝ゾルディック, Irumi Zorudikku) is the eldest son of the Zoldyck Family. At the beginning of the series he appeared under the disguise of Gittarackur (ギタラクル, Gitarakuru) in the 287th Hunter Exam. Also, Illumi is probably the only person that Hisoka can claim as friend, although their relationship is somewhat unconventional.

Appearance
Illumi appears expressionless, like a mask; no one can fathom his thoughts or feelings. He has jet black hair that is very long and combed behind his head, and very dark eyes. To disguise himself as Gittarackur, Illumi uses large round head pins to reconstruct his facial structure, to the point where his voice cannot be recognized. The pins in his chest seem to affect the muscles in his body, as he looks slender without them.

Personality
Illumi for the most part displays very little expression. He holds a twisted and overprotective form of love for his younger brother, Killua. He and his father raised Killua to believe that the only thing sustaining him was darkness, and that he could only have joy in causing the death of others. To ensure that Killua would able to live to carry on the family business, and as a means of protecting his little brother, Illumi implanted a needle in Killua's brain, forcing the latter to run from battles he wasn't sure he could win. He also has an unusual friendship with Hisoka, although it is unclear as to how it developed. Illumi once came to the aid of Hisoka by standing for him as a double in the Phantom Troupe's hideout while Hisoka attempted to find Chrollo. However, when Hisoka asked Illumi would it be okay if he kills Killua, Illumi displayed a horrifying side of himself and asked if Hisoka wanted to die then and there - he acted very similar to how Hisoka did himself after Illumi was opting whether or not to kill Gon during the Hunter Exam, albeit on a much lesser extreme.

Illumi has shown to care for the Zoldyck family members as well. He is willing to handle Alluka's power, even if it costs him his life. He also stated that family members are not allowed to kill during an inner mission (a mission where there is internal conflict), and he does not consider Alluka a member of the family.

Background
Illumi is the eldest son of Silva and Kikyō Zoldyck, and was raised from birth in the art of assassination. He also trained Killua to become an assassin. Illumi was sent by his mother to watch over Killua, who also entered the Hunter Exam. In order to control the development and actions of his younger brother, prior to the series Illumi inserted a needle into Killua's brain, forcing him to run away from the battles he wasn't sure he could win. This needle was later self-extracted by Killua in his battle against Rammot.

Hunter Exam arc
Illumi is briefly seen during the first parts of the Hunter Exam, under the name of Gittarackur and with his appearance highly distorted by his pins. He made his first appearance when Tonpa considers offering him one easily ease, though he almost fails the second phase.

Before the fourth phase on Zevil Island, the examiner Lippo gives each of the 25 remaining candidates a card with a number on it; the fourth stage of the exam is conducted as a manhunt and Lippo warns the candidates that their own badges would be on the line due to every candidate being given the number of another's badge. Gittarackur phones Hisoka and offers his help, but Hisoka turns down the offer. He later finds his target, Gozu, but is interrupted by Sniper, who has Gittarackur as her target and attempts to kill him by sniping at him from a distance. However, she hits Gozu, who is fatally injured. Gittarackur then kills Sniper. Later, he goes to Hisoka and gives him the number badge belonging to Sniper. He then digs a hole and sleeps in it with the two badges until the end of the fourth phase.

The final phase is an elimination tournament where the winners are removed from the tournament and the losers given more chances; winning a match results in the victor receiving his or her Hunter License. Killua is required to fight Gittarackur as his second match after feeling sorry for his first opponent and letting him win. When the match begins, Illumi reveals himself to his little brother. He mentions that his reason for taking the exam was not only to obtain a license, which he needed for an assassination mission, but also to watch over Killua because of their mother's worries about Killua going off on his own. Illumi then tells his brother that he will never make a good Hunter because he cannot break free of his training as an assassin. He says that Killua's only purpose in life is in killing others, and that he is only a puppet and wants nothing. Having severely disoriented him, he asks what it is that Killua expects from becoming a Hunter.

Killua replies that he doesn't really want anything from the Exam, but he does want things. He wants to stop killing people; it's boring. And now that he's met Gon, he wants to be friends with him. Illumi deems it impossible, since he and his father raised Killua to be a cold-blooded assassin. He also says that if Killua were to stay with Gon, he'd eventually hurt or even kill him because it's in his nature. Leorio, upset by Illumi's speech, claims that Gon already views Killua as his friend. Illumi, troubled by this, wants to murder Gon, but realizes that killing him would break the rules of the Exam. He asks Netero if he would be disqualified if he killed Gon after his match with Killua. Netero replies that his actions wouldn't be breaking any rules, since he would already be considered a licensed Hunter. Illumi tells Killua that he will kill Gon unless Killua fights him. This is a trick question, as the needle in Killua's head makes him unable to attack opponents he cannot defeat, and he surrenders. Illumi gets his Hunter License. Illumi does not want to anger Hisoka, so he does not kill Gon.

Gon, awoken from his sleep, hears about how Killua lost and was disqualified for killing a fellow contestant from Satotz. He then asks Illumi to apologize to Killua; however, he doesn't understand Gon's reasoning. Gon claims that Illumi is not qualified to be Killua's brother. Illumi asks if one needs qualification to be a brother. Gon, further angered, lifts Illumi up using one hand and breaks his arm. Netero, who was discussing the topic with everyone else before Gon came in, notes that they are examining the nature of Killua's act. The verdict they arrive at is that Killua was rightfully disqualified, but he is still eligible for the following year's exam.

Illumi, well aware that Gon wouldn't stop bothering him until he knows where Killua is, tells Gon that Killua went home to Kukuroo Mountain. He is later seen discussing with Hisoka on the matter. Hisoka asks Illumi if it was a good idea for him to reveal the location where Killua was. Illumi says that the location is already famous and that there is no harm in revealing it to Gon. Illumi thinks that Gon is dangerous and it would be best if he killed him, but Hisoka, aware of this, warns him that Gon will only die by his hands.

In the 1999 series, Illumi has a fight with Gon after the exam. Gon kicks him in the head by swinging on a vine. Presumably, Illumi let him do this, as Gon is nowhere near the raw speed necessary to land a blow with his own power. He praises Gon's combat potential and is about to kill him for corrupting Killua when he is stopped by Hisoka. He then gives Killua's location, saying that it doesn't matter that he knows because he still can't reach him.

Zoldyck Family arc
In the 2011 series, Illumi appeared in a short flashback when Killua came home from a job. He welcomed Killua home and asked how his work went. Killua knows that Illumi has been watching him so there's no reason to answer the question. Illumi stands beside Killua and tells him their mother Kikyo is waiting inside, but Killua only replies that he doesn't want to see her.

Yorknew City arc
During the Southernpiece Auction in Yorknew City, it is revealed that Illumi is an acquaintance of Chrollo Lucilfer. He, Maha, and Kalluto, are hired by Chrollo to assassinate the Ten Mafia Dons, who placed bounties on the Phantom Troupe's heads. After he accomplishes this mission, Hisoka hires Illumi to disguise himself as him and infiltrate the Phantom Troupe's hideout. Illumi uses Kalluto to distract the members in the hideout while switching places with Hisoka.

Chimera Ant arc
Illumi does not formally appear in this arc; however, he is mentioned many times by Killua. It is also revealed that Illumi is responsible of planting a needle within Killua's brain. Silva and Zeno figure it out shortly after he removes the needle.

13th Hunter Chairman Election arc
Illumi shows up at the Election for the next chairman in his Gittarackur guise. He talks with Hisoka about what had happened during the Chimera Ant crisis, the death of chairman Netero, his younger brother Alluka (whom he wishes to eliminate), and the current situation with Killua. In Killua's flashback, Illumi experimented with Alluka's wish granting ability using a female servant named Kasuga, which resulted in the death of her and 66 other people.

Illumi is seen again sitting with Hisoka in an airship bar. They talk about Alluka's ability. Illumi explains to Hisoka the magnitude of and the rules related to Alluka's power, and tells him that tens of thousands of people, including the Zoldycks and Hisoka, would die if Killua wishes to have Gon restored in the wrong way. He fears that Killua will do it the wrong way — he would have somebody else make a wish and pay the price himself. So he asks Hisoka to help him kill Alluka if he himself fails to persuade Killua to make his wish in a proper and safe way.

While Killua is going to Gon's hospital with Alluka and his servants on a car, Illumi calls him by the phone and asks about the removal of the needle, which Killua confirms. Illumi says he will go into action. Killua then asks if he wants to kill him, to which Illumi replies that family members are forbidden to kill each other in an "inner mission," implying that he does not view Alluka as family and wants to kill Alluka. Killua immediately issues a challenge to Illumi. As soon as that happens, Illumi manipulates the drivers of a car and two trucks to drive Killua's car off the cliff. Watching from a distance, Hisoka remarks that Illumi is too extreme. Illumi replies that he has no choice because Killua is hiding some rules of Alluka's ability and asks Hisoka to eliminate the servants. Hisoka then asks if he can kill Killua, making Illumi explode with anger and give off an intense killing aura for a moment. He suspects this is a deliberate provocation to let Killua know where they are, but Hisoka says it is a joke.

Illumi arrives in an airport to meet up with Hisoka. He knows that Killua used 8 airships to escape them. Hisoka suggests on ambushing the hospital but Illumi tells him it's not a very good idea because Killua's friends are wandering there. Instead, he relies on his needlemen to do the job for him. Killua and Morel creates a plan on capturing the needle humans first, then targeting Illumi. Killua wants to "sell" off his big brother by asking a help to other Hunters. Illumi makes his first move, while Hisoka hunts the "misses" for him.

Hisoka and Illumi talk over the phone after killing the Hunters sent by Teradain, Bushidora and Lupe. Hisoka informs Illumi that he has found a map detailing the airships' paths and destinations. He offers to send Illumi a copy, albeit an altered one, but Illumi says that he also have a map from one of the attackers and that he already knows which airship Killua and Alluka are on. Illumi deduces that the airships will not land any time soon and sets out to aid Hisoka in finishing off the other attackers before going to where Killua and Alluka land. There he gets hold of Hishita and controls him. It is only when Killua and Alluka are already in the car that Killua discovers that Hishita is already under Illumi's control.

Illumi arrives and tells Killua to hand over Alluka to him. Just then, Tsubone also arrives, revealing that she is the 'peeping Tom'. She states that Milluki cooperates with Illumi by sending a video. The Zoldycks may be watching everything through the video feed from her scope. It was an order from Kikyo Zoldyck. Suddenly, Alluka wishes for Tsubone's nail from her middle and ring finger, activating Alluka into his wish-granting mode. Tsubone then tells Killua to make his wish, yet Illumi tells him that Killua may sacrifice dozens of innocent people to save Gon. Illumi states that killing within the family is prohibited, and he is willing to die in order to ensure the whole family's safety. Killua wishes to heal Tsubone's left hand which makes Alluka exhausted. After this, Illumi tells him that he is assured that there is a way to heal Gon without putting Killua at risk. Although, the situation hasn't still erased his doubts as Killua hides something from him. Until Killua doesn't tell everything to him, Alluka will never be free.

Later, Illumi was seen watching from afar and wondered about what would happen if he'd be able to control Alluka's ability, he requested Tsubone to watch, when Alluka started healing Gon he felt a huge force, he started laughing and said that he will have and control it. Illumi was seen approaching the hospital stalking Killua and Alluka again. Upon approaching the hospital room, analyzing Alluka's ability, upon arriving to the room he state's that when he learns how to manage Alluka properly, he will guarantee minimum freedom for Alluka instead of being locked in his room all the time, but Killua stated that he is going to be the one who will protect Alluka, upon asking Killua to hand Nanika over, Killua wakes Nanika up and wishes to make Illumi go home, which Nanika does as Illumi is teleported back to the Zoldyck house, much to the amazement of the entire family. Seeing this made Illumi crave to control Killua in order to control Alluka's abilities.

Abilities & Powers
As an assassin of the Zoldyck Family, Illumi has been trained since birth in assassination. Thanks to his training he possesses rare abilities such as strong resistance to poison, a high tolerance to electricity, great agility and physical strength, and advanced armed and unarmed combat techniques.

Hisoka rates Illumi's overall strength and Nen as 95 points out of 100--even stronger than some members of the Zodiac Twelve.

Nen
Illumi has an incredibly powerful murderous aura which makes Killua fearful and wary whenever he approaches him. He is a Manipulator but his abilities have never been fully revealed. It is unknown how he learned Nen before becoming a professional Hunter.

Trivia

 * It was hinted that Illumi knew Chrollo Lucilfer before the Yorknew City Arc started.
 * Illumi may be from an Italian word (illuminato) which means enlightened, the total opposite of Illumi Zoldyck's personality. However, his name may be related to the Illuminati, which goal is to control the world. Illumi is also a Manipulator, which fits with the Illuminati's goals.
 * In other versions of Hunter x Hunter, Illumi is spelled and pronounced as Yellmi.
 * Illumi-and-Hisoka.jpg the 1999 anime adaptation, there is a bonus stage right after the 3rd phase, in which the candidates are required to collect treasures in order to be provided with a room on a ship for three days. Gittarackur collects treasures with ease, and his first roommate happens to be Tonpa. When a storm approaches them, Gittarackur and Hisoka decide to help Gon's team. Hisoka saves Gon from drowning, while Gittarackur takes over the steering wheel of the ship after Kurapika bumped his head and lost consciousness. The next morning, Hisoka compliments him on his great job, to which Gittarackur only gives him a peace sign. His head is not yet shown at this point but his hair can clearly be seen.
 * In Manga Vol. 30 Chapter: 320 Illumi was shown in the place where voting was held. He was disguised as Gittarackur for the first time since the Hunter Exam Arc.

Quotes

 * (To Killua) "Killing within the family of prohibited. But if you wish "it", that's different. Now then, are you ready to do me in?"
 * "And even if rule five has an exception where it doesn't apply to Killua, I don't mind dying as long as it means the rest of my family will be safe."