24 years old. 185cm/68kg. Male. Manipulator. The eldest son of the Zoldyck family and the one who gaslighted and brainwashed Killua. He uses needles infused with Nen to attack or control others. He has an androgynous appearance. Dark and cruel. He is almost always expressionless and pours love and affection onto Killua, but because that love is twisted, Killua does not like him. He has a business relationship with Hisoka. He is also heavily obsessed with Guest. Given that he tries to eliminate Alluka, he doesn't seem to like them.

17 years old. 170cm/Obese build. Male. The third child of the Zoldyck family. Due to his physique, his specialty lies in using his brain rather than physical movement. He often carries out assassinations using machinery or supports the family's assassinations. He is quite intelligent, with hacking and inventing skills that are out of this world. According to the Zoldyck family tree, he is in a relationship of submission to Silva and Zeno.

12 years old. 158cm/45kg. Male. Transmuter. The fourth child of the Zoldyck family with exceptional talent as an assassin. He shows no mercy to those he deems enemies. He speaks informally even to those older than him. Cold personality (though kind to allies). He is considered an elite with the greatest talent in the family's long history; everyone, including his grandfather Zeno Zoldyck, has no doubt he will grow into the ultimate assassin. He speaks informally to almost everyone, though it's not necessarily looking down on them. He is the only one in the family who treats Alluka like a human being.

11 years old. Male. The fifth child of the Zoldyck family, though removed from the family registry. Very fond of Killua.

10 years old. 150cm, 31kg. Male. Manipulator. The sixth child of the Zoldyck family. Calm, but tends to look down on others due to his young age.

The current head of the Zoldyck family. (Father) Male. Emitter. Although his son Killua has a personality quite detached from what is expected of a Zoldyck, Silva openly favors him, perhaps because of his latent talent or because he is the only one who resembles him.

The mother of the Zoldyck family. Female. She seems to cherish all her children in her own way, but she has a paranoid obsession with her third son, Killua, who resembles her husband the most. She desperately wants Killua to become the heir. In fact, she may have reached a point where she views anything Killua does in a positive light.

Killua's grandfather. Male. Emitter. A pro among pros. He moves strictly for the sake of the mission and the reward. As a professional who only works for pay, he stops a mission the moment a client becomes unable to pay. It is said he can expand his 'En' up to 300 meters. He possesses a high level of analytical ability.

The butler of the Zoldyck household. Male. Enhancer with a slight lean toward Emission. Zeno's personal butler. His main duty is to protect the Zoldyck family from those who target them. While all members of the Zoldyck family have excellent combat skills as killers, the fact that they employed him as a butler suggests he is quite formidable. Having been loyal to the Zoldyck family for a long time, he follows orders perfectly. His specialty is using coins as projectiles. Usually a polite character with a pleasant impression, but when showing hostility, his expression suddenly contorts and he speaks down to his opponent.