Z-one

ZONE is revered by Yliaster as their "god", especially for the Three Emperors, whose goals seem to center around unleashing it. ZONE also is the one responsible for creating Bruno, for the purpose of stopping the trio. Bruno himself has stated that ZONE is somewhat a god of Destiny.

ZONE is the the founder and leader of Yliaster itself, as a mean to set the course of history. It is also said that he wields the "Power of a god who reigns over Time itself". Furthermore this power that is said to be able to destroy everything.

Appearance
ZONE is contained in a machine shaped like either a comma, the number six, or a Japanese magatama (depending on its position). The backside and front-side resemble the Yusei Go's, with all markings identical to that of the Duel Runner, albeit in the exact opposite color scheme (white with red instead of red with white). A more humanoid figure is inside the machine, whose face is mostly covered, but only a portion around his eye is visible, which is the same color, shape, and position as Yusei's eyes. The figure has a marking similar to Yusei's criminal mark. ZONE's helmet/head also is exact to Yusei's helmet (including the yellow diamond in the center front), but also opposite color scheme (white instead of red). His human outfit also shares design with Yusei's jacket, for instance the two gem-like garments on it's collar. A notable fact is when he is upside down, in his comma form, he appeared to help Yusei and co. He saved Yusei, Bruno and Sherry LeBlanc from being blown up in Sector Security. He also gave Yusei his "Shooting Star Dragon" in order to defeat Primo. Since then, he has been shown in his right side up position, plotting to erase New Domino City and kill the Signers, along with Aporia and Sherry. ZONE appears to have Duel Monsters cards in the blue canisters that are on his machine body, it is unknown as of yet what these cards are or what they do for ZONE.

ZONE has also taken the form of Dr. LeBlanc.

Apocalyptic future
ZONE comes from the apocalyptic future devastated by Synchro Monsters and "Machine Emperors", and is one of the few lifeforms remaining in the future world, along with Aporia, Bruno and Paradox.

During the WRGP finals, Aporia shows Team 5D's this vision of the future he came from. On this vision, ZONE along his two comrades appear before Aporia and asks for his help.

ZONE is later made into a God by Aporia, with the help of the older Bruno and Paradox. When Aporia, Bruno and Paradox are put in capsules because of their old age, Aporia begs ZONE to use his powers to stop the future from happening at all costs. Before Aporia dies as well, it insisting to ZONE to split him into three embodiments based on the three despairs of his life. ZONE promised that he would.

World Riding Grand Prix
ZONE first appeared when Sherry and Bruno attempted to scan her "Z-One" card, warping them and Yusei Fudo to a computerized world. After they all woke up near a lake along with Elsworth, Yusei speculated that it has something to do with Yliaster.

Later after reaching a Clear Mind, Yusei finds "Shooting Star Dragon's" Tablet outside the city, upon touching it he is once again transported to where ZONE is. It is there that ZONE gives him the respective card. This is because he has obtained an alternate possibility, meaning Accel Synchro and that same card has the possibility towards it. This is one of the requirements for Clear Mind. ZONE states that Yusei has the right to take it, as he departs saying that "all possibilities must be made equal".

Later, after being separated from Yusei and Bruno, Sherry LeBlanc winds up in the company of ZONE, in the form of her father. ZONE promises Sherry he'd tell her the entire truth of what's going on, but she'd have to accept her fate being altered.

ZONE reappears in episode 131 showing Sherry the future caused by Ener-D. Later on, Primo reveals that it was ZONE who rebuilt/resurrected him.

After Yusei defeats Aporia, the Grand Design is completed, allowing the Arc Cradle in the sky to descend upon New Domino City. ZONE, along the human bodies of Paradox, Bruno, and the real Aporia, is within the Arc Cradle, and recovered the remains of Aporia's mechanical body. There ZONE tells Aporia that although he was defeated, he did not fail completely because the Arc Cradle managed to appear, and some things have changed. ZONE then asks Aporia if he is willing to try to change the future again, to Aporia agreeing to help, because he is ZONE's 'eternal friend'.