Characteristics

They are accompanied by the title Legendary Assassin Family, and it is said they have never failed a requested assassination. Their reputation is world-renowned to the point that anyone who hears the name Zoldyck trembles in fear.

Residence

Their base is a mansion at the summit of Kukuroo Mountain, and the entire mountain is family property. This includes the vast and dense forest surrounding the mountain. Despite being assassins, they operate quite openly, so it is well-known that this place belongs to the Zoldyck family, and outsiders even come for tourism.

"- While the surrounding area has become a famous tourist attraction, that only applies up to the front gate. To enter, one must pass the family's tests.

The first is to manually open and enter the main gate, known as the Testing Gate. No key is needed to open the gate. Anyone with the strength can enter, and the gatekeeper does not stop them. It is a wall-like gate where multiple sizes are connected in layers; the smallest is Gate 1, and the gates get larger as the numbers go up. Crucially, one side of Gate 1 weighs 2 tons, and the weight doubles with each subsequent gate. Gate 1 is 4 tons, Gate 2 is 8 tons, Gate 3 is 16 tons, and so on.

The second method is to enter through the intruder's door, which opens with a single key that can be taken from the gatekeeper. It is suspicious that such a door exists separately, and the gatekeeper even hands over the key without much resistance. However, this is a bait or a trap; entering here means fighting the giant hound, Mike. Usually, bounty hunters mistake this for the Testing Gate, snatch the key from the gatekeeper, enter through the intruder's door, and get eaten by Mike.

In reality, considering that Gon's trio, who had just obtained their Hunter licenses and didn't even know Nen, could open the gate after training, it is just a slightly heavy door in the Hunter world. The actual gatekeeper's role is merely to care for Mike rather than stop outsiders, and Mike never attacks anyone who enters through the Testing Gate. Thus, the actual security of the Zoldyck household depends on the butlers encountered after opening the Testing Gate. Upon entry, one enters a massive forest, and these butlers are so powerful that an average Hunter could be wiped out by a single apprentice butler.

Family Traditions

Despite being the world's best assassin family, their personal information is quite boldly exposed. They don't use aliases or hide their faces, and their actual address and phone number are printed right on the business cards they hand out. There's no need to contact them through some dark web site to make a request; you just call the number on the card. The residence is treated as a tourist attraction, except for the interior.

Their assassination method is also to just charge in head-on with superhuman combat abilities and take the target's head personally. It's closer to contract killing than stealthy assassination. Of course, while not shown, they might kill quietly or disguise it as an accidental death if the client wishes. Given that Killua is shown walking silently or hiding his presence, they certainly use stealth techniques. To create human weapons with such combat power, they receive harsh education from childhood, such as developing immunity to poisons and enduring pain from powerful electric currents. Killua, even at a young age, could calmly take a nap while being whipped.

They have their own family rules, and when a family member commits a significant act of rebellion, they are strictly sanctioned. The sanction levels seem to range from Level 1 to Level 5. At Level 4, various restrictions apply even when going out, such as being accompanied by a butler. Level 5 is a total ban on going out. Even while facing such sanctions, Killua simply thought, 'I've made Father quite angry.'

It is unknown what level of sanction it was when Killua first ran away and returned to be whipped by his older brother Milluki. However, judging by Killua's attitude of sleeping through the beating, it doesn't seem to have been a very high-level sanction. Since the people in this family have bodies capable of lifting dozens of tons, ordinary punishments don't work due to their physical endurance, so they inevitably(?) resort to torture. Because they are naturally so tough, most corporal punishment is ineffective. In fact, seeing Killua's lack of damage and his comment that he 'let him hit me out of guilt,' it's highly likely it wasn't an official sanction. Since Milluki is overwhelmingly the weakest in combat power in the Zoldyck family, including the youngest, he cannot cause actual harm to any family member, making it meaningless to entrust him with punishment.

Due to the nature of their business, they place little value on the lives of others, but the lives of family members seem to carry different weight. When Killua ran away with Alluka and threatened his mother's life, even his father gave in. Deadly combat between family members is also forbidden. However, Alluka is such an exceptional case that Silva said, 'Do not think of Alluka as family,' and Illumi actually tried to kill Alluka.

When opinions differ among family members, they have a tradition of not necessarily coordinating through dialogue but using any means necessary to carry out their own will. This is known as an internal family mission. In the Yorknew City arc, Illumi, Silva, and Zeno Zoldyck even held an assassination speed contest against each other's clients.

Surprisingly, other than performing assassinations with professional spirit, they don't seem to have fixed principles regarding murder. For example, Zeno Zoldyck felt troubled after unintentionally seriously injuring Komugi during a mission, saying it was the first time since taking over the family business that he might have killed someone unrelated to the request, whereas Illumi kills even civilians without hesitation to achieve his goals.

Furthermore, strict give-and-take is the rule even among family members; when exchanging anything of value, including information, they give and receive compensation under the name of a 'trade.' At this time, they make a declaration: 'I swear on the trade.' Examples include when Killua got information about Greed Island from Milluki, or when Silva asked Milluki about Alluka's ability... And this 'trade' seems to be a very important, unbreakable rule in the Zoldyck family. Even between Milluki and Killua, who have a bad relationship and not a shred of trust, they thoroughly believe that 'the information is certain because it was obtained through a trade' and 'he's not stupid enough to mess around in a trade.' Give and Take

Family Members

Maha Zoldyck (Great-Great-Grandfather)
Zigg Zoldyck (Presumed Great-Grandfather)
Zeno Zoldyck (Grandfather)
Silva Zoldyck (Father)
Kikyo Zoldyck (Mother)
Illumi Zoldyck (1st child)
Guest (2nd child)
Milluki Zoldyck (3rd child)
Killua Zoldyck (4th child)
Alluka Zoldyck (5th child)
Kalluto Zoldyck (6th child)

Butlers

Regardless of gender, they wear black suits and take care of all aspects of the Zoldyck family's life. They are on a different level from simple gatekeepers; even an apprentice can easily crush an average pro Hunter. They are the ultimate combat butlers. It is no exaggeration to call them a private army.

Despite being such characters, their lives are treated almost like consumables. It is unclear how they are recruited, but due to the harsh working environment, it is presumed many have no relatives. Almost all whose origins are known are from Meteor City. It seems they have a separate butler training center where they live together and are taught various subjects to be thoroughly raised.

They are surprisingly human, and many butlers cherish Killua, who wants to have friends and is kind-hearted. In Gotoh's case, he thought of Killua like his own child, and considering the warm relationship between the butler Mitsuba and Alluka, one might doubt if this is really an assassin family. And they seem to have their own personal networks. Butlers are forbidden from dating and face the death penalty if caught, but it seems some do it secretly. Of course, that doesn't mean they escape the family's surveillance... Meanwhile, there are butlers in family relationships, such as Amane calling Tsubone grandmother, though it's unknown if they are adoptees or actual family. If they are actual family, it seems some butlers are allowed to start families with the Zoldyck family's permission.