Number

"Number" ( Nanbāzu) is an archetype of special Xyz Monsters. According to Yu-Gi-Oh! ZEXAL, there are 100 of them; so far, 37 are in a known character's possession while 27 are known by name, and 2 Chaos versions.

Story
When Yuma Tsukumo unlocked the Door with his Emperor's Key, he opened a portal between his own and another dimension, which allowed Astral to come into his world. Yuma found himself trapped within a sphere of blank cards, which shortly flew away. By crossing into Yuma's world, Astral's memories got transformed into the 99 "Number" cards and scattered in unknown directions. In order to regain his lost memories, Astral teamed up with Yuma.

"Numbers" appear to be blank cards that take the form of whoever finds them desires the most, and design themselves to fit their original owner's Decks and keeps that form forever. Some Duelists may have more than one "Number" which fits their Deck. When they are Summoned, their respective numbers are printed on their users, appearing in such places as the forehead, neck, left and right hands (in Syuta Hayami's case, it appeared under his right eye and in Number 56's Holder, it appeared in his left shoulder).

They have been shown to be very dangerous, as their users are easily possessed by their power, with the exception of Yuma due to the Emperor's Key, Kite Tenjo's Photon Transformation, and the Tron Family's Crests. To be noted, however, the power of Photon Transformation and the Crest seem to be limited, not to mention the dire consequences, in respect of these being used to wield a "Number" card as they will drastically exhaust their user.

It is said that these "Number" monsters cannot be destroyed with cards in this world. "Number" monsters can only be defeated by other "Number" monsters. However, when two or more "Numbers" confront themselves in a Duel they'll fight each other to consume one another. When a "Number" is defeated in a Duel by Yuma, Yuma obtains it, and its power is absorbed into Astral. Also when Yuma defeats a "Number" monster Astral gains another part of his memory.

In the anime, Astral mentions there are 99 "Numbers", but according to Kite Tenjo, there are 100 "Numbers". As Astral already had 1 of the "Numbers", "Utopia", it is possible Astral was referring to the other 99 "Numbers". However, Dr. Faker believes that, aside from 99 "Numbers" which are Astral's pieces of memory, Astral himself is a "Number", the original one (ナンバーズのオリジナル, Nanbāzu no Orijinaru). On the other hand, the manga is obvious about their number. When Astral obtained a memory piece from "Number 17", he said his memory is divided into 100 "Number" cards. This amount of number is later confirmed by both Kite Tenjo and Mr. Heartland.

One of the "Numbers", Dark Mist, attempted to take control of Astral and steal the "Numbers" Astral collected for himself. After his defeat he was absorbed again. It later escaped again claiming that the other "Numbers" helped him escape because they all want the same: destruction. According to him, Astral originally also wants to destroy everything and urges him to remember his mission. However, another "Number", Utopia, protected Astral from Dark Mist, suggesting that not all the "Numbers" want the same.

Abilities
In the anime, "Numbers" have a few "special" abilities that are unique, such as "Numbers" can only be destroyed by other "Numbers". However, the effect stating that "Numbers" can only be destroyed by another "Number" is a monster effect, and therefore, can be negated. Also, a monster who is treated as a "Number" can destroy them, meaning they are not invincible.

In the anime, some "Numbers" also have certain abilities, such as "Number 7: Lucky Straight" being able to steal other competitors' "Numbers" and Xyz's through its incredible luck, helping Charlie escape the Heartland police, or short circuiting a train into moving on its own. "Number 25: Force Focus" even gave Syuta the power to predict the future through his photographs.

The "Numbers" amplify the darkness and desires of humans, whether these cause good or bad. When Summoned, "Numbers" take on what appears to be a sealed form, and when the "Number" starts to transform into their artwork, the "Number" then appears. When a "Number" is defeated, they are absorbed into Astral, and can be used by any Duelist whom Astral is currently with. Each "Number" contains a piece of Astral's memory, which he recovers each time he absorbs one.

They are also known to manipulate their user into summoning them as soon as possible, sometimes to the point of cheating as seen with Scorch and Chills. "Numbers" also manipulate their users into protecting them at any cost, as seen when "Number 83: Galaxy Queen" made Nelson Andrews believe that she was his mother. Thus, he equipped her with "Furious Max's Curse" to protect her from being destroyed by battle, and changed the attack target to his "ESPer Star Sparrow" via "Star Sparrow Forever!", causing him to lose the Duel.

A person possessed by a "Number" easily becomes addicted to their power and desires to obtain more "Numbers". . "Number 7: Lucky Straight" however did not seem to have this effect; neither Charlie McCoy nor the girl he eventually gave it to were shown to be adversely affected by it, but it did seem to give the holder incredible luck. Though when Charlie Summoned "Number 7" in his Duel against Yuma, the number appeared on his hand. There's a possibility that instead of using its own influence to corrupt its owner, it corrupts the owner by making them addicted and very reliant on the luck it offers.

When a "Number" monster is Summoned or taken by control, the number of the card appears somewhere on the card holder's body in the form of curved lines and a dot. Only Yuma and Kite are excluded from this phenomenon. Bronk Stone remained uncontrolled when controlling "Utopia" and Reginald Kastle when he controlled "Acid Golem", but that was due to Yuma's Emperor Key they had. Others such as, Fortuno when he controlled "Shock Master" and "Big Eye", and Charlie McCoy with "Lucky Straight" remained uninfluenced, but the respective numbers still appeared on their bodies.

The process of how a "Number" takes control is shown more in depth. It is shown that a Number converses with whoever currently controls it, unless the owner has a way to ward off the Number's influence it tries to take control by destroying or possibly merging with what appears to be the person's soul. This could be why when the Photon Hand retrieves a "Number", it pulls out the holders soul along with the "Number" and why a "Number" seems to be hidden inside the holders soul. Same case is with Astral whom when extracting a Number, the card itself appears from within the person whom was possessed.

Only strong willed-people, like Shark, seem to have the power to resist "Numbers" power. Also, not all "Numbers" take over their owners, as shown when Charlie McCoy gave "Lucky Straight" to his niece. Instead of transferring its influence to take over the child, "Lucky Straight" transferred its luck so she would successfully get through a serious surgery.

Some of the "Numbers" are shown to be somewhat sentient and capable of communication. Two examples are Number 83: Galaxy Queen, and Number 96: Dark Mist. Another might be Number 32: Shark Drake. In the English dub, when someone gets a hold of the "Number", the voice tells them to "let the Number take hold."

Members
Each "Number" monster has its respective number appearing on a part of its body. 37 out of 100 "Numbers" are shown here; 27 by name. 2 "Number C", or "Chaos Numbers" (an evolution of the originals) are also known.

Number C (Chaos Numbers)
"Numbers C" (read as Chaos Numbers) are upgraded versions of the base "Numbers", which are Summoned by overlaying their base counterpart through Chaos Xyz Evolution.

Trivia

 * In the anime, their card texts are in a strange language that nobody except Astral, Kite, and those possessed by "Numbers" can read. This is removed in the dub, as with all other card texts and is replaced by the image being blurred.


 * In the anime, "Numbers" use a different style of Xyz Summon than regular Xyz Monsters. Regular Xyz Summons use a red colored spiral portal, but "Numbers" use a galaxy style portal.


 * In the anime, they have something to do with the large structure made up of gears inside the Emperor's Key as seen when Astral presents the "Leviathan Dragon" and "Galaxy Queen" before their corresponding numbers printed on gears inside it which glow making all the gears in the structure turn.


 * Xyz Monsters are said to come from an another dimension just like Astral, this probably explains why "Numbers" are Xyz Monsters. Xyz Monsters are also said to be made of antimatter.


 * According to Satoshi Kuwabara, all "Numbers'" numbers are not chosen randomly, but are decided "carefully, with attention to details that can make the fans enjoy it in various places", with many puns and second meanings for each Number.


 * "Numbers" do not have a sealed form in the manga.