Limit: Over

Author's Note: An alternate take on the events of Yu-Gi-Oh! 5D's (and Yu-Gi-Oh! Duel Monsters and Yu-Gi-Oh! GX by extension), with side references to Yu-Gi-Oh! ZEXAL and the Yu-Gi-Oh! 5D's manga. The end of the world occurs much earlier here, in Yusei's mid-thirties. Enjoy the story and R&R.

Disclaimer: I do not own anything related to or of the Yu-Gi-Oh! 5D's series.

Summary:

A character study of Z-one, in an alternate universe where Z-one was never a scientist who inherited Yusei's legend, but actually Yusei himself.

Yuki Judai leapt from building to building in Venice, propelled by his spirit-powered superhuman abilities. Above, the tri-headed behemoth, Cyber End Dragon, circled, intermittently lobbing its Eternal Evolution Burst and razing the landscape. Judai's perfectly executed vaults allowed him to emerge unscathed, but a second leviathan, Rainbow Dragon, unexpectedly flanked, cutting off his escape.

"I summon Neos!" he announced, slapping the card onto his Duel Disk.

Judai's reality-altering magic augmented the Duel Disk's Solid Vision projection, manifesting his servant as flesh and blood. The Elemental Hero blocked, shielding his master from his best friend's ace's Over the Rainbow attack.

A masked blond anachronism, responsible for commandeering these creatures' loyalties, extolled the fruition of his experiment in this era to Judai.

Invisible, even to the heterochromatic sight of the teenage do-gooder, the monolithic magatama that was Z-one hovered in the clouds. The android facsimile Z-one built of his dead associate, Paradox, was following his programming to the letter.

The Crimson Dragon roared, blazing a wall in front of Judai to defend against the Shooting Sonic beam unleashed by the stolen Stardust Dragon. Fudo Yusei arrived from the future aboard his D-Wheel, the Yusei Go, in the feathered serpent's wake.

Right on schedule, Z-one commended.

Z-one. The last human. Alpha and Omega. Deus ex machina. A literal god from the machine. That had not always been his name. He'd been conferred many. Adonai, Elohim, YHWH.

No, he reminded himself.

He had been Fudo Yusei once. The very same Fudo Yusei he was looking at now.

Sixteen years after the Crimson Dragon brought Yusei to this period, humankind would be wiped out. Humans would succumb to their greed, touting Synchro Monsters as the proof of their evolution. Momentum, which the late Dr. Fudo pioneered, would spin out of control, mobilizing the Machine Emperors, and then Zero Reverse would consume the globe.

For this reason, the one formerly known as Fudo Yusei sought a different path. Achieving Clear Mind and Accel Synchro, he charted a route away from assured obliteration. Alas, it was not enough. He needed to push harder if he intended to save everybody from the brink.

Thus, Delta Accel Synchro was born. Having improved his D-Wheel and discovered a frame of alertness exceeding clarity, Top Clear Mind, he redefined the impossible. The effulgent Cosmic Blazar Dragon flying behind him, he could finally avert catastrophe. But it was not to be.

Delta Accel Synchro took his D-Wheel superluminal, faster than the speed of light. Without the technological enhancements Z-one was currently fitted with, Yusei was ripped to shreds and thrown across the annals of history until he arrived, shepherded astride the glare of a holy obelisk, at the nexus of belief, the genesis of the macrocosm.

His body almost gone and an eye offered as tribute, held together only by his Signer descent, he stared up at the bearded face of the Almighty. In that moment of absolute supplication and fear, the five Dragon Birthmarks converged like wishes on Yusei's back, calling forth the Crimson Dragon. Within the infinite emptiness, the two deities clashed, trying to absorb each other. A second or eternity – Yusei was not sure which – passed, and Quetzalcoatl won, subjugating the cross-bearing Hand of Creation into a card. It possessed no title, but Yusei knew it instantly: Sephylon. Laying his eye on it for the first (?) time, Yusei experienced an Akashic storm. The omniscience of God, he grabbed with a burnt hand. The source code of the universe, its metamorphic numeral fractals spread like a network of lotus roots throughout time and space. What had been a vast nothingness became an infinite light, Ain Soph Ohr.

Yet in that wellspring of knowledge, Yusei realized a frightening truth. Humanity's fate had always been his doing, the mistake of his grand design. For as soon as Sephylon came into being, from the reverse of the card appeared gentlemanly and skeletal Sabatiel, clad in black robes. Blue-eyed, he was the original of Yusei's angels and his opposite, presiding not over life or death, but their contradiction, nihility. With his newfound divinity, Yusei peered far, scrutinizing the destroyed future from which he hailed. Sabatiel, nay Darkness, was the embodiment of his failure. He had tried to correct mankind's course, but was instead himself the progenitor of the species' promised extinction.

Aware what had to be accomplished, he began his task shaping the nascent universe. To start, he separated the Light of Destruction from the Just Darkness. In between, his breath animated Neo Space, setting the stage for Yuki Judai to delay Darkness' encroachment and to meet his past self at their temporal byroad.

Burying Sephylon deep in the clockwork of the hidden Da'at, he planted the primal seed necessary for the development of lifeforms. This planetary particle grew into an existence-spanning tree, its emanations permeating the cosmos. Ruling over these attributes were ten of his mechanoid archangels.

Metaion, the firebreather, carried his writ.

Lazion, the purifier, who purged the dead.

Zaphion, the clear water, anointed his pontiffs.

Sadion, the whirlwind, who partitioned benedictions.

Kamion, the shaker of terrain, governed fortitude.

Michion, the fiery sword, who was his ambassador.

Hailon, the uterine symbol of fertility, cultivated growth.

Raphion, the freezing tempest, who sang healing hymns.

Gabrion, the flood, proclaimed his approach.

Sandaion, the sainted thunder, who amassed prayers.

On Earth, Yusei watched Atlantis sink beneath the ocean. In Ancient Egypt, he witnessed the battle between the Nameless Pharaoh and Zorc Necrophades. He rewrote Iliaster's ambitions. Sent the radiant surge that plunged the world into war. Struck down Pegasus J. Crawford's wife, and led him to the origin of Duel Monsters. Precipitated the Ishtar family tragedy.

Yusei was playing the longest game of all.

With Paradox's business complete and both Judai and his younger incarnation poised to intercept Paradox during Muto Yugi's golden years, Z-one travelled to the future to oversee his own trip to the past, then even further so he could officially enlist Antinomy, Paradox, and Aporia in their epoch and adopt his new name, closing the loop.

Adrift the uncharacteristically still tides of Momentum, Z-one perceived a distortion in the timestream. Somewhere, an alternate version of him had successfully defied a god and been presented three aftermaths: to be king of the future, to be Satellite's saviour, or to fight alongside the Duel Kings of legend. All three eventualities had already corporealized.

It gave Z-one hope. Despite how pessimistic this sojourn left him, there continued to be renditions of him convinced humanity was capable of change. His contingency plan was in motion. Yusei would surely come for him. And when they collided, they would undo this rapture he caused. Which would triumph, he wondered. His youthful idealism or his despair-wrought wisdom?

Beyond the limits of time, the souls of Iliadus stirred in the temple of the Lord. The Ark Cradle dropped, inching ever closer to Neo Domino City.