Aporia

Aporia is the true form of the Three Emperors of Yliaster, Jakob, Primo and Lester. Each one of them is a different part of his lifetime: Lester being his childhood, Primo in his early midlife, and Jakob his older days. Aporia comes from an apocalyptic future world, which he sees as a failure by humans, and is determined to change history, to protect the world and to ensure it will never be destroyed by humanity's errors.

The name "Aporia" comes from the Greek word "ἀπορία", which literally means question or wonder and is used in philosophy to refer to a philosophical puzzle or state of puzzlement, and, in rhetoric, a rhetorically useful expression of doubt. It may also derive from another Greek word "απόρροια", which literally means result.

Childhood
As the world was evolving at an ever-increasing rate, and the human race became dependent on the Ener-D system, and Synchro Summons, which were the gears that accelerated the spin of the Ener-D system. The Ener-D system began to spin faster and faster, and eventually, the speed became uncontrollable.

At the same time, an invasion of Machine Emperors were set upon the world, and the world was sent to ruin after the invasion. All life forms in the world had been vanquished, by the subsequent Machine Emperor invasion.

As a child, Aporia, along with his mother and father, was chased by a Machine Emperor Grannel Infinity. The Machine Emperor fired a beam at them, killing his parents. He regarded the loss of the people that loved him as one of three major despairs in his life.

Adulthood
At some point in his life, Aporia met and fell in love with a fellow freedom fighter, whom he fought the Machine Emperors with.

They later attempt to ambush a Machine Emperor Grannel together using rocket launchers. However, the Machine Emperor retaliates by blowing up half the building they were shooting from, taking Aporia's lover with it. Aporia regarded the loss of the one he loved as the second of three major despairs in his life.

Old age
The Ener-D eventually changed and spun in the opposite direction, sparking a global disaster. in his old age, Aporia found himself alone. He initially believed himself to be the only survivor and regarded having no one left to love as the third of three major despairs of his life.

Aporia soon found he wasn't the only survivor as he met Vizor, ZONE and Paradox. Being the last survivors of this world, the four of them believed it to be their mission to create a better future.

They tried to dispose of the core power of Ener-D, which wiped out the world before. They performed countless experiments to try and find a solution to restore the world to the way it once was. However eventually ZONE had become more mechanical and Vizor and Paradox died. Aporia considered himself to be the only one left alive.

As Aporia was about to die, he placed himself in a capsule. He asked ZONE to do whatever it took to prevent their future from ever occurring, and insisted that ZONE split him into three embodiments based on the three despairs of his life. ZONE promised that he would.

Embodiments of despair
Keeping his word, ZONE split Aporia's being into three android-like embodiments of despair, Lester, Primo and Jakob, who were sent back in time. The three of them became the Three Emperors of Yliaster and used their power of falsification of history to alter the current events in time, including having themselves enrolled into the World Racing Grand Prix as Team New World. . Team New World faced Team 5D's in the final event of the tournament. When both teams were down to their last duelist, Yusei Fudo destroyed Jakob's "Machine Emperor Grannel Infinity" with "Shooting Star Dragon". The three embodiments then combined back into Aporia again.

World Racing Grand Prix final
Aporia took over Yusei and Jakob's Duel and proceeded to Summon his "Machine Divine Emperor Machinecle Infinity", overwhelming Yusei and putting him at a severe disadvantage. Aporia showed Team 5D's the future world from which he had came from and explained that he was going to remove New Domino City from history to prevent it from happening. However Yusei refused to believe that humans were the reason that the future world had been destroyed, and continued to fight on. Yusei managed to Summon "Red Nova Dragon", "Black-Winged Dragon" and "Shooting Star Dragon" and use them to defeat Aporia. Contrary to what Aporia had expected, the Grand Design was completed despite his loss and the Ark Cradle began to descend on New Domino.

ZONE managed to recover Aporia's mechanical body and took it to the Ark Cradle, where his human body still resided. ZONE informed him of the Ark Cradle's appearance over New Domino despite the loss. ZONE explained that an outside interference has caused the future to change. ZONE asked if Aporia was willing to try to change the future again, only for him to respond that he would do anything. Aporia felt much obliged, as he regarded ZONE as his eternal friend. Tools then began to repair Aporia's mechanical body.

With his repairs fully competed, Aporia nows stands protecting the second Gear where he is challenged by Jack, Leo, and Luna. In a 3-on-1 duel, they are forcibly equipped with machines that inflict real damage. After summoning Machine Divine Emperor Dragon Asterisk and his Machine Imperial Soldiers and finally by activating several Burning cards, Aporia reduces Jack and Luna's life points to 700 and 100 respectively. Leo begins crying Aporia simply ends his turn after explaining to Leo that what he is feeling is true despair. However, Jack shows Leo how to never give into despair and keep believing in hope. After doing so, Jack's life points are reduced to 100, but Leo begins acting as Jack and Luna's shield.

Abilities
Just as Jakob, and Primo, Aporia can fuse with his Duel Runner, and is the one with the most connections to the Duel Runner. His Duel Runner is probably the largest seen in the series. It is a combination of Jakob's Runner, the Terrible Omen, and Lester's Duel Board, and bears a resemblance to the Duel Runner used by Paradox in the The 10th Anniversary Movie with color, and the front shape. Aporia is able to use telepathy, as he was using it communicate with ZONE after his body was recovered. It can be noticed that that Aporia's current body is an android much like the Three Emperors with the qualities of the real person. This is proven as the Ark Cradle is holding the capsules that contain the bodies of Paradox, Bruno, and the human Aporia. He also has been revealed to use the ring behind his head as his duel disk like Lester using his duel ring. Aporia can also combine with his Field Spell Fortissimo the Moving Fortress in almost the same way as his duel runner once activated. During Aporia's duel with Jack Atlas, Leo and Luna it is revealed that he fuses with the machines in this way as it makes him feel more like a machine which has no emotions as he wants to forget about the amount of misery he sustained in the future via his embodiments.

Anime
Aporia's Ground Deck is a Machine Emperor-themed Burn Deck which focuses on dealing effect damage to the opponent via his field spell Fortissimo the Moving Fortress as well as the additional cards to his field spell such as Level Cannon and Lock-On Laser. He utilizes cards such as Damage Boost to punish anti-Burning severely. His ground deck also focuses on swarming the field with Machine Imperial Soldiers which are based on his embodiments Machine Emperors and summoning his ace monster Machine Divine Emperor Dragon Asterisk.

Aporia wasn't shown owning any deck for a Turbo Duel on his own. He was only once involved in a Turbo Duel using the deck of his strongest embodiment, Jakob.