Dust's 'Da' from the Japanese spelling of Dark Zone (Dāku Zōn).

Ultima's 'U' from the English spelling of United Sanctuary.Their names are also based off of the nation they represent:.The title naming theme is based off of common elements throughout fiction, similar to the Cray Elementals.Messiah had no alternative but to seal the dragon bones in another planet with brimming lifeforce. However, Gyze's dominion had depleted Cray and the planet could not bear to seal the dragon bones. The optimal measure was to seal the dragon bones in a planet's innermost core so that none could approach it. Nonetheless, the cores of the Zeroth Dragons, the dragon bones, host Gyze's immense grudge, and even Messiah could not completely nullify it. Though the Zeroth Dragons had decimated numerous warriors of light with their powers beyond mens' wisdom, they were eventually suppressed by the unyielding warriors, and were put to an end together with Gyze by Messiah. The six 'Zeroth Dragons' spawned by this method were named 'Distant Sea', 'Inferno', 'Death Garden', 'End of the World', 'Destroy Star' and 'Zenith Peak'. The dragon bone absorbed all the spirits of the place and formed dragon bodies according to the nature of the lands. First, Gyze drove the gigantic wedge 'Dragon Bone of Destruction' into lands abundant of spirits. They are pseudo-'Transcendent Lifeforms', and they resemble formless spirits more than common lifeforms. The Dragon Deity of Destruction, 'Gyze', had once completely dominated the land of Cray, and spawned these destruction weapons by fusing spirits of the planet with his own power. Zeroth Dragons, the Destruction Weapons Spawned by Gyze They also have their own nation-specific foiling in their respective booster sets, as well as being released purely in ZR rarity. Likewise, they have a new mechanic called Ultimate Stride, which allows them to Stride upon any clan of their respective nation. They are cards without a printed clan, but a nation's name instead, which makes them belong to the clans from that nation. In the anime, they are used by Gyze's Apostles, each of them corresponding to the respective nation of their decks. They also share the symbol called the 'Mark of Gyze' (on the top of the head for Meggido, Drachma and Zoa, the chest on Dust, the back of Stark and the sword of Ultima). The apostles of Gyze plan to use these dragons to revive him, bringing Planet Cray into an era of destruction and chaos by trying to defeat the Messiah. The Zeroth Dragons are weapons of mass destruction born from the Dragon Deity of Destruction, Gyze.

'Zeroth Dragon' (ゼロスドラゴン Zerosu Doragon) is a race featured on one card of each nation, and introduced in G Booster Set 13: Ultimate Stride. The Zeroth Dragons before Chronojet Dragon G from Jo no Ka opening

Shadow era yari deck