Mythyrian Numbers

Legendary "Number", pluralized as Legendary "Numbers" in the Japanese version, are "Number" cards which are unique located in Number ruins across the world, protected by guardians. They play a major part of the Legendary Number War and Barian Emperor Onslaught arcs of Yu-Gi-Oh! ZEXAL. So far, each one of these cards has been based on figures from history, as the canon portrays it.

Design
Legendary "Numbers" are part of original 100 "Number" cards, but unique. Each of these "Numbers" correspond to a legend inscribed on the walls of the ruins, telling the story of the person who occupied that location in a previous era, before they became ruins due to the ravages of time. Mach, for example, was a Pegasus who served a legendary knight, Dumon. Three knights who lived in his land attempted to usurp the King, but were intercepted by Mach and his master. Since the hero was unwilling to kill his former comrades, both master and steed were eventually defeated and killed. However, the hero's fellow knights regretted their actions and they buried him and Mach together. Mach later became the Legendary "Number" spirit guardian of "Number 44: Sky Pegasus".

History
In Yu-Gi-Oh! ZEXAL, the Legendary "Numbers" are unique "Numbers" whose cards were used by Astral eons ago to seal Don Thousand in the Barian World's Sea of Ill Intent. If Astral obtains them all, he would discover the location of the Numeron Code. However, if the Barian deity Don Thousand obtains them all, he would be fully revived, which later turns out to be false as Don Thousand himself revealed to Yuma and Astral that if all 7 of the Legendary Numbers are obtained from the ruins, his power will then be restored completely.

There is a connection between the Legendary "Numbers" and the Seven Barian Emperors, which was revealed when Astral absorbed "Numbers" "44" and "54". He saw Dumon's past life as a knight owning a Pegasus and Alito's past life as a gladiator. Don Thousand hinted at Vector's past life as a mad king. When Astral questioned Jinlong if the person he was talking about was Mizar, the latter confirmed this. However, Mizar, even with Jinlong revealing Mizar's past life as a dragon tamer, refused to believe he was once a human. Afterwards, Roku found a statue of a military commander named Kiraku Souhachi at the Duel Lodge, which bore great resemblance to the Barian Emperor Girag, with Ponta confirming that Kiraku Souhachi was, indeed, Girag's past life as a military commander.

When Vector released Don Thousand, Thousand revealed that in order to fully revive him, Vector must collect these seven "Legendary Number" cards. Later, Vector convinced Mizar and Dumon to take part in this endeavor, with the assistance of Mr. Heartland, who is now an insect. Also, Yuma Tsukumo and Astral resolved to obtain the "Legendary Numbers" after receiving a message from the former's father.

In the first of the ruins, Yuma obtained the first Legendary "Number", "Number 44: Sky Pegasus", from Mach.

Next, "Dark Mist" acquired the second Legendary "Number", "Number 65: Djinn Buster" from Battle Ox.

After that, Alito acquired the third Legendary "Number", "Number 54: Lion Heart" from Number 54's guardian, but gave it to Nistro so he could control him. After they lost the Tag Duel, Nistro gave Yuma the "Number".

The group next set off to the fourth set of ruins, where Kite began a Duel with Jinlong, whom he subsequently defeats, obtaining "Number 46: Dragluon".

Returning to Heartland City, Yuma discovered by television that yet another "Number" was found, this time inside the Duel Lodge, and rushed to take it. Girag went to the same ruins, but Ponta took over his body and challenged Yuma to a Duel for "Number 64: Ronin Raccoon Sandayu" and Girag's body. Yuma won and obtained the "Number".

When the Different Dimension Airship crashed at sea, Rio was called to the bottom of the sea by the guardian Abyss. Following her along with Yuma and Astral, Shark eventually defeated Abyss' "Number 73: Abyss Splash" after being shown memories from his past life, using the ruins' second Legendary "Number", "Number 94: Crystal Zero", putting most of the "Legendary Numbers" into the possession of Yuma and his allies.

Yuma and Astral defeated Number 96: Dark Mist at the cost of Astral sacrificing himself to protect Yuma from a fatal attack, leaving Number 65's in Vector's control due to his absorption of the Forbidden Number's sealed form after his return to its progenitor - Don Thousand.

If these cards or their corresponding Number Cs clash with the corresponding "Number 10X" (or "Number C10X") they awaken the original memories of the legendary figure described in the ruins. This also causes any malignant influence from Don Thousand to disappear from the respective Emperor.

"Number 54" was used by Yuma to emancipate Alito from Don Thousand's control after it clashed with "Number C105," restoring Alito's real memories and revealed Don Thousand to be instigator behind his tragic death.

Number 64 was to given to Alito by Yuma in order to release Girag from Don Thousand's control with the aid of Ponta, who returned after having been eaten by Girag. Alito succeeded in releasing Griag's true memories in a duel, but he (along with Girag and Ponta) were absorbed by Vector (who obtained "Number 64" along with them).

During their duel on the Moon, Kite summoned "Number 46" against Mizar's "Number C107" and awakened the Barian's true memories. After winning the Duel, "Number 46," along with "Number 107" and "Number 62" unite into "Number 100: Numeron Dragon", which Kite receives. After acknowledging Mizar's superiority as a dragon master, Kite gives the "Number 100" card to Mizar before dying.

During Vector and Nasch's duel, Nasch was able to take control of Number C65 and have it defeat Number C104 causing Vector's original memories to be awakened.

Legendary Numbers
Seven Legendary "Numbers" have been confirmed, with two gaining Chaos upgrades - "Number C65: King Overfiend" and "Number C73: Abyss Supra". Current owners are bolded.