Kalluto Zoldyck

Kalluto Zoldyck (カルト＝ゾルディック Karuto Zorudikku) is the younger brother of Killua. He was initially introduced accompanying his mother during Gon's retrieval of Killua from Kukuroo Mountain. Kalluto appears again during the Phantom Troupe arc, assisting his older brother Illumi with the assassination of the ten mafia dons that had placed bounty on the Phantom Troupe's heads. After the Phantom Troupe's entrance into Greed Island, Kalluto joins as Hisoka's replacement. During the Phantom Troupe's assault on Zazan's palace in Meteor City, he reveals he joined the Spiders with the intention of finding his missing older brother Alluka.

Many are confused about Kalluto's gender. In the manga, it is said that the Zoldyck family has five sons but when Gon, Kurapica and Leorio went to Kukuru Mountain to visit Killua, Killua's mother introduced Kalluto as a 'she'. Kalluto has the ability to manipulate paper, using a paper fan and confetti as a weapon. By creating a paper doll of a person and attaching a small piece of paper to that person's body, Kalluto's ability allows him to hear anything said within the vicinity of that person.
 * Nen Ability:

Kalluto also uses Confetti as a weapon. By flinging at an enemy with his fan, he can locate weak points depending on where the confetti sticks. Kalluto then sends a concentrated stream of confetti snaking through the air, cutting or piercing that location on his opponent.