Illumi Zoldyck

Illumi Zoldyck (イルミ＝ゾルディック, Irumi Zorudikku) is an antagonist from the manga Hunter × Hunter by Yoshihiro Togashi, and 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.

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 used special pins to reconsruct his facial structure to the point where he can only be recognized by his voice.

Personality
Illumi for the most part displays very little expression. He holds a twisted and emotionless love for 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 unusal friendship with Hisoka, although it is unclear as to how it had developed. Illumi once came to the aid of Hisoka by standing for him as a double in the Troupe's hideout while Hisoka attempted to find Chrollo.

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 Kikyō Zoldyck, 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 only revealed his true self near the end of the Hunter examination. Through almost the entire exam, he was in the disguise of a man named Gittarackur. Illumi was sent by his mother Kikyo, to watch over Killua, who ran away from home after injuring both their mother and brother Milluki and entered the Hunter Exam.

Gittarackur made his first appearance when Tompa wanted to offer him one of his laxative spiked drinks, but admitted being frightened by Illumi's appearance. Gittarackur passed the the first and third stage with ease, though he almost failed the second stage. Before the fourth stage on Zevil Island began, the examiner Lippo gave each of the 24 remaining candidates a card with a number on it and stated that this stage the exam would mainly be about capturing the tags with the numbers given to them, and warned them that their own candidate tags would be on the line because every candidate had been given the number of another candidate's tag. Gittarackur phoned Hisoka and offered him some help, but Hisoka turned down the offer. He later found his target, Gozu, an old martial artist, but was interupted by Spa, who was attempting to kill her target, Gittarackur, by sniping at him from a distance. However, Gozu took the shot in the back and was fatally injured. Gittarackur then killed Spa for interfering with his battle. He later went to Hisoka, gave him the tag belonging to Spa, and said that he would be sleeping until the end of the exam.

The final stage was an elimination tournament with a twist. The winners were removed from the tournament and the losers given more chances, and the person that won a match would get his or her own Hunter license. As the exam went on Killua eventually had to fight Gittarackur. With Killua still unaware of who Gittarackur was, he revealed himself to be his brother Illumi. Illumi revealed that he participated in the exam to watch over Killua because their mother was worried about Killua going off on his own, and that Killua might even enjoy being a Hunter. Illumi said that he too wanted to be a Hunter, but only because it would make his job as an assassin easier. Illumi stated that Killua wouldn't be able to become a Hunter because he was nothing more than a puppet of darkness, that his only joy in life was to kill others, and that Killua had no desire, no passion, nor ambition in him. Illumi continued with his psychological attacks on Killua, asking what was it that he expected from being a hunter.

Killua replied that he never wanted to be a hunter, and there was something he wanted. Illumi asks what he wanted, and Killua said that he wanted to be friends with Gon. Illumi says that it was impossible, since he and his father raised Killua to be an assassin. He also said that if Killua were to stay with Gon, he'd only hurt him or even kill him because Killua is a natural born killer. Leorio, upset by Illumi's speech, claimed that Gon already viewed Killua as his friend. Illumi, troubled by this, wanted to go kill Gon, but was stopped by the other contestants and examiners. Realizing that if he killed Gon now, he'd only end up being disqualified, Illumi asked Netero if he killed Gon after his match with Killua he wouldn't be disqualified. Netero said that wouldn't be breaking any rules, since he would already be considered a Hunter. Illumi then told Killua that if he didn't win against him, he'd be willing to spare Gon's life. Killua admitted defeat. Illumi thus won the match, and became eligible for a hunter license.

Gon, who had awaken from his sleep, heard about how Killua had lost and had been disqualified for killing a fellow contestant from Satotz. He then asked Illumi to apologize to Killua, Illumi on the other hand didn't understand why Gon said so. Gon claimed that Illumi was not qualified to be Killua's brother. Illumi asked ironically if one needed qualifications to be a brother. Gon, who was now even further angered, lifted Illumi up using one hand, a feat that surprised everyone in the room. Netero, who had been discussing the topic with everyone else before Gon came in, said that they were examining the nature of the Killua's act. The verdict they arrived at was that Killua had rightly been diqualified, but he was still eligible for the next year exam.

Illumi was well aware that Gon wouldn't stop bothering until he knew were Killua was so he told Gon that KIllua was at their home on Kukuroo Mountain. He was later seen discussing with Hisoka on the matter. Hisoka asked Illumi if it was all right for him to reveal the location where Killua was. Illumi said that the location was already famous, and there was no harm in revealing it to Gon. He thought to himself that Gon was dangerous, and it would be best if he killed him, but Hisoka, who was aware of Illumi's thoughts on the subject, warned him that Gon is his, and that he would only die by his hands.

Yorknew City
In the Yorknew City arc, it was revealed that Illumi was an acquaintance of both Hisoka and Chrollo Lucilfer, though he had known the former far longer than he had known the latter. He, Maha and Kalluto, were hired by Chrollo to assassinate the Ten Mafia Dons who placed bounties on the Phantom Troupe's heads. After he accomplished this mission, Hisoka hired Illumi to disguise as him and infiltrate the Phantom Troupe's hideout. Illumi used Kalluto to distract the members in the hideout while switching places with Hisoka.

New Hunter Chairman Election
Illumi showed up at the Chairman election in his Gittarackur disguise, and talked with Hisoka about what had happened during the Chimera Ant crisis, the death of chairman Netero, his younger brother Alluka, whom he wished to eliminate, and the current situation of Killua. In Killua's flashback, Illumi experimented with Alluka's wish granting ability using a female servant named Yasuha, which resulted in the death of her and 66 other people.

Later, he was seen again while sitting with Hisoka at a bar in an airship. They were talking about Alluka's ability. He explained to Hisoka the magnitude of and the rules related to Alluka's power and told him that tens of thousands of people, including the Zoldycks and Hisoka, would die if Killua wished to have Gon restored in the wrong way. Illumi was sure that Killua would do it the wrong way: Killua would have somebody else make a wish and pay the price himself. So he wanted Hisoka to help him kill Alluka if he himself failed to persuade Killua to make his wish in a proper and safe way.

Abilities
As an assassin of the Zoldyck Family, Illumi was 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.

Nen Ability
Illumi is a Manipulation user but his abilities have never been fully revealed. It is unknown how he learned nen before becoming a professional Hunter. Illumi has been shown to use large round head needles to alter the shape of his own body and others'. Without the needles, he is able to maintain the transformation for around five hours. He can use this ability to infiltrate into places where his targets may reside, as shown when he fooled the Phantom Troupe into thinking he was Hisoka after switching places with him in the Phantom Troupe's hideout.

Trivia

 * It was hinted that Illumi have known Chrollo Lucilfer before the Yorknew Arc started.