Number

The "Numbers" are a set of 100 Xyz Monsters that are included in the show Yu-Gi-Oh! ZEXAL. Supposedly pieces of the mysterious entity Astral, the protagonist of the show, Yuma Tsukumo, must acquire all 100 and solve the mysteries behind these powerful creatures. These monsters can possess people to enact their wills, which usually entails causing destruction, chaos, mayhem, and despair. In ZEXAL, Numbers cannot be destroyed as a result of battle except against another Number, and they all have their number somewhere on their body.

However, there are also alternate Numbers from other universes. In some realities, these Numbers have replaced other Numbers from the original Duel Monsters universe. For example, in one alternate reality, Kotori, Yuma's love interest, gains Number 13: Paradise to help out Number 39: Utopia. Plus, some bearers of the Factorial Numbers possess normal Numbers as well, such as Chris Muir, who has Number 48: XX-Saber Twinbladeknight and Number 66: X-Saber Bariza to help out Number 7!: X-Saber Brink. Since these Numbers are from different universes, some Numbers in one reality will be completely different Numbers in others, allowing for different cards to have the same Number.

The "Chaos Numbers" are a new set of Xyz Monsters recently introduced in ZEXAL. They seem to be upgrades of Numbers, but how and why is not yet certain. All that is known is that they use the previous Number as an Xyz Material, along with the previous Number's materials, and have rather powerful effects.

The "Factorial Numbers" are a semi-related subset of Numbers, consisting of one Xyz Monster from each Type, which all of them either belong to or support a popular Archetype, be it canon or original. They have been scattered across the Duel Monsters multiverse by the enigmatic entity Protsu, and will be used by both DATEA, an evil organization wishing to conquer all universes, and those few that are fighting to free the Duel Monsters multiverse from DATEA's slowly-strengthening grip. The Factorial Numbers are said to be fragments of...

The "Irrational Numbers", also called "Remote Dragons", are 6 legendary dragons, one of each Attribute, that were the guardians of the Architects' home universe. Since the demise of the dimensional-spanning civilization, these cards have been scattered to the four winds across the Duel Monsters multiverse, but the Factorial Numbers will be used to find these legendary monstrosities and revive them, allowing the holders to either save the Duel Monsters multiverse, or enslave it. The Irrational Numbers are all high-Rank Xyz Monsters with the same effect their anime counterparts have, as well as incredibly powerful effects that can easily change the outcome of the duel in the favor of the user.

Finally, there are the "Lost Numbers", a very small group of Xynchro Monsters. All of them are "00", and they all have more general requirements than "Multinetwork God Yotta Byte". However, they are very few and very far between.