Luna

Luna, aka Ruka or Luca in the Japanese version. She is Leo's fraternal twin sister, and a Signer who possessed the front claw Mark of the Dragon. She and Leo aid Yusei Fudo, whom they admire and support, in his Duels.

Luna tends to get tired right after a Duel. She has the ability to communicate with Duel Monsters after having spent ample time with Duel Spirits in a different dimension during a coma. Much to her brother Leo's irritation, she tends to candidly point out the various flaws in his plans, but does deeply care for her brother.

Appearance
Luna's usual outfit is similar to her brother Leo's, consisting of a light pink short-sleeved jacket over a long-sleeved red shirt with golden markings. She also wears light purple shorts with a red belt and sneakers with black and pink markings and high socks. She has gray-gold eyes just like her brother.

On formal occasions, Luna wears a pink dress, a white cardigan and a pink ribbon below her neck. When she's sleeping, she wears pink pajamas with a nightcap. If at school, she wears the New Domino academy girls uniform with a red bookbag.

Luna's green hair is done up in two high ponytails on either side of her head with two shoulder-length bangs on both sides of her face.

Her Duel Disk has a pink and white trim. It was modified by Yusei to fit her left arm.

Personality
Luna is the younger, frail, calmer, more collected of the twins (in the english version this is changed to her being somewhat snobby, and tends to insult Leo, but she becomes more nice to him after the Dark Signer war and starts to act more like her original counter part).

Yu-Gi-Oh! 5D's (Manga)
Both Luna and Leo were left to fend for themselves at a young age. In order to acquire money, the pair began to compete in Turbo Duels, even against adults where they were a raging success. But this was short lived as Luna fell ill, leaving Leo to Duel by himself. After losing, Leo was threatened by Nicolas as he couldn't afford to pay his side of the bet, leading to him getting beat up. Lazar witnessed this and promised to help Luna in exchange for Leo to undergo the Duel Dragon ceremony, which he accepted; acquiring "Power Tool Mecha Dragon" in the process. Some time after this. Luna underwent the same ceremony, acquiring "Ancient Pixie Dragon" as a result.

During the preliminaries of the D1 Grand Prix, Luna appeared with her brother, Dueling under the command of Rex Goodwin to find those suitable for "Duel Dragons". During this, they Dueled and defeated several duelists, including Aria. During this, Luna sat back and watched "Ancient Pixie Dragon" and "Power Tool Mecha Dragon" assault him, with the force of their Feel destroying his Duel Runner whilst Luna claimed that Aria was weak and boring. During the attack, one of "Power Tool Mecha Dragon's" screwdriver missles almost killed two innocent by-standers, but they were protected by Crow Hogan and his "Blackwing Tamer - Hawk Joe the Jet Black". Luna later observed Rex's speech to the finalists about the finals taking place in Satellite. In addition, he informs them that he dispatched Leo and Luna into the finals as only the best should remain.

Luna later appeared along with her brother, insulting Leo for thinking his name is important. The siblings were insulted by Crow who mocked that it was too late for them to be awake, but they merely brushed it off and insulted him back. When Leo revealed his "Power Tool Mecha Dragon" to Yusei and Crow, Luna was shocked to see that they could sense its shadow miasma. Leo then began a Duel with Yusei, where Luna informed him to not involve her as he started it. During the Duel, Luna insulted Leo's tactics, even to the extent that she threatened to harm him if he allowed Yusei to destroy her "Forest" monsters. She also asked Leo to let her get off of their Duel Runner when he transformed her monsters into "Morphtronics" via "Morphtronicize". As the Duel continued, Luna insulted Leo for bragging, telling him to shut up. When Yusei activated "Sword Dance", one of the blades struck Luna, which angered Leo, causing him to heavily assault Yusei, reducing his Life Pointss to 200. Yusei attempted to reason with Leo, but he vowed to destroy Yusei for harming Luna.

Yusei then proceeded to use his "Gravity Warrior" to take advantage of Leo's strategy, increasing its ATK to 7100. Luna notices "Dark Bribe" in Leo's hand, stating that Leo underestimated Yusei's strategy. She then insults his performance, stating that he dug his own grave. Yusei then speeds up, passing the twins and launched his attack. Before it hit, Leo stood up, preventing Yusei's sense from harming Luna. After the Duel, Luna insults Yusei, stating that the Duel was boring. She then informs Yusei that she's the only one who's allowed to bully Leo and proceeds to threaten him, emitting a shadow miasma. Seeing this, Leo tells her that they completed their mission before disappearing, telling Yusei they'll see him in Satellite.

The next day, Luna and Leo were present on the ship headed to Satellite for the finals. During which, they were enjoying the food provided until Crow appeared, insulting the pair for being happy, despite their loss to Yusei. This resulted in an argument which annoyed Luna at first, but she then joined in, insulting Crow's hair. An omake revealed that she watched an eating contest between Leo and Crow as they didn't have access to their Duel Runners to settle their argument.

Later, Leo and Luna are shown to have passed to the tournament's second stage. Their first opponent was Tetsu Trudge, but the twins defeated him with ease. Luna even called him weak.

Next, Luna is reading a fairy-tale book. She comments on the book like if it was a real story, and says that she must defeat the "dark wizard". Leo sadly notes how she is acting strange. Goodwin then appears to them as a hologram. He tells them that they must defeat the "dark wizard", and Luna realizes he is Yusei. Leo asks if that will bring Luna back to normal, and Goodwin confirms it. However, Goodwin's plans are only to test Yusei's Duel Dragon's strength, and for that, he needed to use another Duel Dragon. Leo and Luna then go after Yusei.

Background
Luna lives together with her twin brother Leo in the Tops residential area. They spend most of their time alone together as their parents are usually at work. They were initially educated via the internet, so they spend most of their time inside. Later they went to the Duel Academy.

Luna has been Dueling since the age of three. Once, she lapsed into a coma after a Duel, and did not awaken for a month.

During that month, her mind lived in the Duel Monsters Spirit World under the protection of Ancient Fairy Dragon, one of the Signer Dragons. Before waking up, she promised she would always be there to defend the Duel Spirits from evil that threatened the land. However, the pressure from undertaking such a task alone was too much and Luna had to forsake her promise, allowing the Duel Monsters Spirit World to fall later into the influence of Zeman the Ape King, who without much difficulty with the help of his army, turned most of the spirits into stone, and eventually imprisoned them. He was even able to capture and rock-seal Ancient Fairy Dragon's spirit into the mountains. Luna later returns and saves the spirits with some help from Leo.

Fortune Cup Saga
Luna was selected as someone to participate in the Fortune Cup. She was told she was randomly selected, but was invited so Yliaster could confirm that she is a Signer. However, not up to participating, Leo planned to disguise himself as her and Duel in her place.

Due to their Marks, Luna was able to sense Yusei when he was shocked by the police officers. She and Leo rescued him after his Duel with Trudge and took him to their home. Yusei wanted to leave, feeling that he was putting them in danger, but Leo talked him into a Duel. After Yusei won, Luna and Leo manage to get him to stay for the night. They awake the next morning to find that Yusei had left after modifying their Duel Disks to fit their small arms.

The next day, Leo entered the Fortune Cup disguised as Luna, but using Zigzix's Signer-detecting technology, Lazar was not only able to determine that Greiger Dueled Leo instead of Luna, but also that Luna is a Signer.

Luna faced off against Professor Frank due to Rex Goodwin's consolation game, but in the middle of the Duel, both her and Leo are hypnotized. Luna's conscious self awakens in the World of Duel Monster Spirits, where she sees the degradation of the dimension and decides to uphold her promise from then on. Before she concludes the match, Luna is called a Signer by Frank, although unaware at that moment of its meaning or its relationship with her Claw Mark of the Dragon.

Only Yusei becomes aware of her being one, though he does not tell the others. Eventually, though, they learn this after his Duel against Akiza Izinski. She witnesses for the first time the appearance of the Crimson Dragon during Yusei and Jack Atlas' title Duel. Because of the Duel, Luna, along with the 3 other Signers, are transported to an alternate dimension. There they are shown 2 visions; one of the Stairway to the Dragon Star, where the People of the Stars were worshiping the ancient Signers, and the other showing Satellite being destroyed, and in its place the appearance of a spider mark shines.

After that, Luna and Akiza are the only ones to witness Jack's defeat. As they all return to the stadium, she reunites with Yusei in order to leave through an underground tunnel. Luna talks to Yusei about the vision, who responds that he doesn't know what it means, but that in any case he must prevent it from happening. She also asks him what is a Signer, to which Tenzen Yanagi intervenes in order to answer to her. Luna learns its meaning and its relationship with her along birthmark, along with the fact that that Yusei, Jack, and Akiza are Signers too.

Dark Signers Saga
After the Dark Signers started taking action, Luna has been having vivid dreams of the Five Dragons and the Crimson Dragon battling an unknown evil. Ancient Fairy Dragon gets pulled into an abyss, showing that the Dragon's card is currently with the Dark Signers.

As Yusei is about to come face to face with Kalin Kessler, his Mark of the Dragon reacts along with Luna, Jack, and Akiza's. She notices this and Leo does too as he is nearby. Luna is able to sense that Yusei is the reason of why her Mark of the Dragon glows. After Yusei takes a hit by "Earthbound Immortal - Ccapac Apu", Luna's Mark of the Dragon gets etched onto her arm.

Leo explains to Tanner and Yanagi that Luna is frail and therefore she can't go out much. Luna accompanies Leo, Tanner, and Yanagi to the Arcadia Movement, where they meet Sayer. He induces them to sleep with gas, wanting to make Luna a member of the organization due to her powers. Luna wakes up next to Akiza, where they both watch the Duel between Sayer and Leo. Akiza tells Luna that Sayer wants to test her brother to find out if he possesses any similar powers. Leo passes out upon losing as Luna calls out to him.

After the Duel, Akiza informs her that Leo isn't in danger. Luna clarifies Leo doesn't possess any powers, but he was still kept in a place with Luna. Akiza tells her that in any case the Arcadia Movement will be her new home, as she doesn't want Luna to walk through the same path she did; the path of being feared and abandoned by others because of her powers. Luna asks Ancient Fairy Dragon for help, but her spirit says that she cannot rescue her and that she is witnessing the posing threat of the Dark Signers. In order to set her free, Luna must join forces with her servant, Regulus, who will eventually appear to her. Once Ancient Fairy Dragon is set free, she promises to protect Luna from the enemy.

After Bolt Tanner frees her and Leo, while fleeing the building, she senses Akiza in a Duel as her Mark of the Dragon begins to glow. As she decides to find her, the four of them run into Misty and Akiza's Duel. As Luna notices the lizard Dark mark, she recalls the vision of the battle between the Crimson Dragon and the Earthbound Immortals again. Right as Misty is about to Summon her Earthbound Immortal, Luna's dragon birthmark protects her, Leo, Bolt, and Yanagi from being sacrificed to Summon Misty's Earthbound Immortal. Tanner gets her and Leo out in time as the building collapses.

After Akiza lands in the hospital in a comatose state, Luna is there along with her brother and Jack. As with the rest of the people there, she witnesses the Duel between Yusei and Akiza. After it concludes, Akiza decides to help them in their fight against the Dark Signers. After it, Luna along with Leo and the other Signers are invited by Rex Goodwin into his house, as he wants to reveal to them some secret concerning the Crimson Dragon.

She learns from him that those who are Signers exist within some sort of "fate", derived from the Crimson Dragon's power, one which cannot be escaped from. That strange fate was the one responsible for that all of the four Signers to have actually met in someway. Thus, the "Fate of the Signers" unites each and every one of Yusei, Jack, Akiza and her own destiny together in order to guide them all.

Nonetheless, according to Goodwin the four of them are not only Duelists chosen by the Crimson Dragon itself, but they are also the reincarnations of the ancient Signers themselves. Also already predicted thousands of years ago the four of them would encounter one another. She also learns about the Dark Signers' abilities involving their powers and use of the Earthbound Immortals. According to Goodwin, their powers that manifest in a Duel come from the underworld. Also as they appeared on the city, many casualties occurred just like in Satellite due to their Immortals. Luna along with the others realize the shocking truth behind the transformation of an individual into a Dark Signer: It can't be reverted due to the fact those individuals are dead and that they are resurrected because of a powerful phenomenon occurring on the other side of the Underworld.

After this she cheers Leo up, who feels he can't be a hero or protect her because of having lost to Sayer, by saying he doesn't have to be a hero, and to just protect her like he always has.

Like Jack and Akiza, she's present along with her brother during and after Yusei's match against Roman Goodwin. After it concludes, the rest of the Dark Signers show themselves, as their ancient battle is about to commence. Later on as each one of the Signers is set on defeating their respective opponent, they split up to each of the four control units of the Original Ener-D Reactor. As Luna and Leo are taken by Trudge to where Devack is waiting, she instead travels into the Duel Monsters Spirit World in order to free Ancient Fairy Dragon. Due to this, Leo bravely challenges Devack to a Duel in her place, as he is determined to fulfill his promise of protecting her.

In the Spirit World, Luna enters the Minus World in search of Regulus. She gets chased down by an army of monkey spirits commanded by Zeman the Ape King, who is Devack's Dark Synchro Monster. The monkey army captures "Kuribon", "Sunny Pixie", and "Sunlight Unicorn". She evades them with the help of a spirit named Torunka. Luna eventually finds Regulus at Pojar Forest and tells to the Lion the promise long ago made to Ancient Fairy Dragon. However, because of the Cursed Needle in its ankle, he understands her in the opposite way. After a chase, Luna is finally able to dispose of the Needle and convince the White Lion of her righteous intentions by showing her Mark of the Dragon. After that Regulus, Luna, and Torunka set off to Zeman's castle. They are able to get inside by tricking Zeman into thinking that Luna is a servant of Zeman and has caught Regulus. She also tells Zeman to curse both Regulus and Ancient Fairy Dragon in order to minus Ancient Fairy Dragon completely. Zeman falls for this and is about to release her.

However, Zeman finds out they were trying to trick him and orders his army to attack them. He is eventually killed by Regulus, and at the same moment, Leo defeats him in the real world. Devack then Summons his "Earthbound Immortal Cusillu" and attacks Leo, who withstands the assault. Torunka sends Luna back to the real world, where she helps her brother. Devack then attempts to use Ancient Fairy Dragon against Luna, but she forces him to sacrifice it in order to save his Earthbound Immortal from being destroyed, which allows her to Summon her Dragon to her side of the field. Once this is done, Regulus appears and breaks the Dragons' chains freeing it at last. Luna then proceeds to use both "Ancient Fairy Dragon", equipped with "Pain to Power", and "Power Tool Dragon", equipped with "Rocket Pilder", to destroy Cusillu and defeat Devack.

After the Duel, Luna picks up "Ancient Fairy Dragon's" card, and she also discovers a "Regulus" Monster Card, indicating that he will return in a future Duel.

Following Crow's unexpected Shadow Turbo Duel against Greiger, Luna along with her brother, Trudge, and Crow himself witness the rematch between Yusei and Kalin Kessler. After the extreme Duel between the 2 finally ends, Luna, Leo, and Trudge accompany Yusei as he decides to go to the Original Ener-D Reactor directly in order to Duel against Roman one more time.

She watches the Duel between Yusei and Roman as it ends up with Yusei´s victory. After the Duel, she watches in horror as Roman blows up the bridge and drops Yusei into the Ener-D Reactor. Like the rest she´s glad, when Yusei returns, though unconscious. After he finally wakes up and that everyone eventually goes up through the same stairs they used before, they all notice purple sparks in the distance. She then knows that not only has Jack won, but also activated the third Tower.

Knowing that the last Tower to be activated is Akiza´s task, Luna along with Leo, Trudge, and Yusei all go to where it is. Arriving at an old and abandoned carnival, they split and began looking for her and Mina, except for the twins who look for them together. After Sayer awakens Akiza's power and is transformed once again into the Black Rose, they notice the tornado that has materialized on the carnival caused by the Synchro Summoning of "Black Rose Dragon". As they get to the area where the Duel is taking place, they both notice Akiza´s powers having once again manifested even stronger. After Mina and Trudge arrive, they all watch the outcome of the match, with Akiza emerging victorious. However, they notice that its too late for the last Tower to be activated, as the sun has already set.

The Condor geoglyph appears in the sky, while the King of the Netherworld revives from the Original Ener-D Reactor's crater. Kuribon appears to Luna, telling her that they mustn't let the King reach the Condor geoglyph. As the King begins moving towards it, the Crimson Dragon appears and transports Luna and her companions to Rex Goodwin's mansion, where the Condor geoglyph is located. Goodwin stands at the top of the Stairway to the Dragon Star, where he reveals himself to be the final Dark Signer and attaches Roman's arm to himself.

Goodwin declares that a Shadow Turbo Duel will be held within the Condor geoglyph as a ritual to welcome the King of the Netherworld. As Yusei, Jack, and Crow accept the Duel in order to stop the resurrection of the Underworld Ruler, Luna and the rest of the party cheer for them. However, when "Earthbound Immortal Wiraqocha Rasca" is Summoned, it tries to cheat by Summoning a flock of demonic black birds to attack Yusei, Jack, and Crow. Akiza and Luna are able to provide aid by manifesting Black Rose Dragon and Ancient Fairy Dragon to fight the horde.

World Racing Grand Prix Saga
According to the third opening, it appears that Luna has enlisted into the New Domino City Duel Academy along with Leo. Dexter also accompanies them as the 3 of them are pupils of Miss Bartlet. After Yusei saves them from being expelled from Duel Academy, she goes missing in the Forest were people are reported to disappear. There, she meets Haley and he brings her to his house. Leo goes looking for her while Dexter goes to get Yusei. She is then trapped in the bedroom of Haley's sister, Claire. Luna finds out that Claire and Haley are actually dead, while Leo Duels Haley because Haley thinks Leo is going to hurt his little sister. When Yusei arrives, Leo asks Yusei to help Luna and leave him Dueling Haley. Yusei gets in and assists Luna. Luna wants to help the spirit of Claire who is still in the house and finds a special card. Leo defeats Haley and Luna is free. Luna gives Haley the special card and Haley and Claire disappear.

She and her brother appear to cheer up Akiza on her first day of riding a Duel Runner, and watch her progress. After that they follow Yusei and Akiza to a skating ring to learn some tricks on how use the Duel Runner. They both comment on whether it is a date or not between the two, and she agrees at some point.

When Lester enrolls in Duel Academy, he's admired by the students, especially Luna, though her brother suspects something odd about him and tries to keep a distance between him and his sister. Lester invites Luna to his home and shows her how to use a Duel Board. The next day she tries to practice with the Duel Board Lester gave her, and finds her brother practicing as well. But their fun is short-lived as Lester, in his Yliaster uniform, steps in and Duels the two of them, with Luna unable to escape due to her Duel Board moving on its own.

At one point in the Duel, Luna was almost blown off the track, but is rescued by Regulus, much to Lester's surprise. Lester quickly Summons his newly acquired monster, "Machine Emperor Skiel Infinity", to fight the twins. Luna Summons "Ancient Fairy Dragon" for the first time and inflicts some damage to Lester. But she's unaware of "Skiel's" frightening ability and it absorbs her monster. Leo Summons "Power Tool Dragon", but Lester quickly upgrades "Skiel" and attacks her brother directly, almost killing him, but he's saved by the Crimson Dragon at the last second (she also feels a piercing heartbeat for unexplained reasons). Luna then proceeds in Dueling Lester. He attacks her directly with "Skiel", but is protected by the physical attack of "Skiel" with the help of the monsters in her Deck. Lester escaped after the Duel ended. After that, the twins try to seek out Lester but every trace of him disappeared, even the mansion and the memories of anyone else who knew him. She, along with Leo, are members of Team 5D's pit crew.

Ark Cradle Saga
After the finals of the WRGP, Luna, along with Leo, Bruno, and Akiza, are celebrating the victory of Team 5D's when the Divine Temple descends from the sky. When they learn from Sherry LeBlanc that Yusei will die if he enters the cradle, Luna cries, stating that she doesn't want to lose him. Yusei assures her that nothing will happen to him. She, along with the rest of Team 5D's, begin to travel to the Divine Temple. However, the gang gets split into three groups due to Z-one's trickery. She travels with Leo and Jack to the center of the temple.

Soon after splitting up, Luna, Leo, and Jack come across Aporia, who challenges them to a Duel where all damage to their life points becomes real damage to their lives. Luna and Jack are quickly knocked around by Aporia despite Leo's best efforts to protect them. As Luna is barely hanging on by 100 life points, Leo soon becomes Aporia's new target, unleashing as many card effects as possible on him. When Luna watches as Leo Summons "Power Tool Dragon" and "Ancient Fairy Dragon" to protect them and is assaulted by the effects of Aporia's cards which leads to his death, she begins to cry over Leo, and her life points begin slowly dropping due to Aporia's devices. In this battle, Leo finally awakens as a Signer. He then Summons Life Stream Dragon, which saves Luna and Jack by increasing their Life Points to 2000 with its effect. Luna soon realizes that Leo's new dragon is the one she saw in the vision of the 5,000 year-old battle she saw. Luna, Leo, and Jack then defeat Aporia with their dragons and head for the Support Gear.

After Yusei defeats Antinomy, she, along with Jack and Leo, reunites with Yusei and, inside the Support Gear, finds Z-one. During the battle against Aporia, Aporia himself realised that what he felt was not despair, but hope. Aporia appears in the Support Gear and Duels against Z-one to remind him of such hope. However, he loses. Realizing the power of Z-one's Deck and following everyone else's example, along with her brother, she gives Yusei her "Ancient Fairy Dragon" in order to help him in the final battle against Z-one.

Team 5D's Future
About half a year after the battle with Z-one, the twins receive a letter from their parents. In it, they tell them that they want to live together, but for that to happen, they may have to leave New Domino City. Luna and her brother are unable to decide what to do because they want to stay with the gang. After Jack challenges Yusei to a Duel and he agrees, the twins along with Akiza and Crow watch the Duel. Leo and Luna end up moving to be together with their parents.

In the next eight years, she loses her pigtails, and hangs out with some new friends at a school she attends.

Yu-Gi-Oh! 3D Bonds Beyond Time
Yusei Fudo had a nightmare about the Zero Reverse incident that his father created. With Yusei upset, Jack Atlas and Crow Hogan decided to have a Turbo Duel to cheer Yusei up. After driving down the highway, Paradox, who traveled back in Yusei's time, challenges Yusei to a Turbo Duel. After a few turns, Yusei tunes "Junk Synchron" with "Junk Warrior" and Synchro Summons "Stardust Dragon", but Paradox reveals a blank card and launches a beam at "Stardust Dragon", absorbing it and creating a blackened corrupt card of it into the blank card. Yusei confronts Paradox, who shows him the corrupt card, before vanishing through time again. Yusei, Jack and Crow halt their Duel Runners and look in bewilderment at the original "Stardust Dragon" card, whose illustration has just been blanked.

Yusei, Jack and Crow then started questioning about Paradox's identity at their garage, when Akiza Izinski, Leo and Luna arrived and showed the archives they found about the past. They found an old article about "Maximillion Pegasus" and "Yugi Muto", with Yusei recognizing Yugi as a legendary duelist. They also discovered a record of "Stardust Dragon" assaulting various duelists in Europe. Knowing that "Stardust Dragon" could not have existed in that era, Yusei zooms in on the article's picture to discover Paradox standing in the background of the dragons. Outside, New Domino City begins to crumble and collapse. Witnessing the destruction, Jack Atlas realized that "Stardust Dragon's" existence in the past is now changing the future, which is their era.

With the support of the other Signers, their marks begin to glow as the complete Crimson Dragon appears on Yusei's back followed by Yusei's Duel Runner glowing as well. Yusei feels himself being called by the Crimson Dragon and beckons Yusei to board his runner. With its help, a time slip is opened and Yusei begins his chase after Paradox.

In Venice, Paradox finds Jaden Yuki, who still has the powers of Yubel and The Supreme King. Paradox attacks him with "Cyber End Dragon" and "Rainbow Dragon". Jaden manages to resist by Summoning "Elemental HERO Neos" to protect him. In response, Paradox Summons "Stardust Dragon", a monster from the future, and proceeds to overwhelm Jaden (This scene is how the movie opens before changing to Yusei's nightmare of Zero Reverse). Stardust Dragon's first attack almost destroys Neos and sends the two skidding backwards into a wall.

As Paradox commands Stardust Dragon to attack Jaden again, Yusei appears with the Crimson Dragon, who takes the blows for Jaden. Paradox disappears once again.

Soon, Yusei and Jaden began to chat on a roof. Seeing Yusei's Duel Runner, Jaden gets excited seeing such a technology, asking Yusei if that was the Duel Disk of the future. He then explained that he came here because he heard that there were cards missing from duelists. Yusei explains to Jaden that Paradox is trying to change the past and that his target was Maximillion Pegasus. Jaden then used his laptop to find out an article about the event that Paradox performed that would create a major historical event. (In the English version, Jaden did not believe Yusei, which is why he opened his laptop and discovered that truth.) Jaden then checks his card, as his "Elemental HERO Neos" card turns into a blank card. As the country began to collapse, Yusei tells Jaden that they must hurry to save the world.

Yusei and Jaden then ride Yusei's Duel Runner, with the Crimson Dragon taking both of them even further back in time.

Meanwhile, in Yugi's timeline, sometime after Battle City but before the Waking the Dragons arc, Maximillion Pegasus is currently holding a tournament. The [http://en.wikipedia.org/wiki/Sakiyomi_Jan_Bang! Sakiyomi Jan Bang! ] made a cameo as the MC of the event. Yugi and his grandfather, Solomon Muto, noticed "Stardust Dragon", "Cyber End Dragon" and "Rainbow Dragon" in the sky. Paradox then attacks the crowd with "Cyber End Dragon" and "Stardust Dragon", killing almost everyone, including Pegasus and Yugi's grandfather.

Amongst the ruins, Yugi is the only survivor against Paradox's attack. He stands up and searches for other survivors. He finds a bandanna belonging to his grandfather and cries over his death. He then sees Paradox laughing on top of a building, happy that he finally completed his mission. At that moment a crack in the space appears and the Crimson Dragon suddenly "swallows" Yugi. Then, Yugi is thrown back in time at the same place half an hour earlier. Yusei and Jaden find Yugi and explain to him what they know about Paradox to him. Yugi agrees to fight with them against Paradox to free the trapped monsters and save the world.

At the event, Jaden Summons Yubel and starts to scare the audience, so they would flee. By doing so, Yugi hopes the future is safe as Jaden regains his "Elemental HERO Neos" card. However, Paradox arrives regardless to the shock of the heroes. After Paradox took his mask off and introduced himself, Yugi asks Paradox what kind of person he is. Paradox replies that he is from a future which was destroyed by Duel Monsters. He intends to destroy the game of Duel Monsters to prevent that future from happening. Yusei tries to tell Paradox that by changing time and trying to destroy Duel Monsters, he will also erase people from the timeline as well, to which Paradox replies that it is what he is looking forward to the most. Yusei, Yugi and Jaden challenge Paradox to a 3 on 1 Duel, with a time limit of 20 minutes, before Pegasus arrives at the event and the other dimensions crumble to pieces. Jaden's eves change color as Yubel appears behind him and Yusei's Mark of the Dragon glows as the Crimson Dragon roars behind him as the two Duel Kings say their catchphrases and then Yami says to Yugi that the Duel against Paradox would be the toughest and Yugi responds by saying that they should rise to the challenge. Yugi transforms into Yami and says his catchphrase as Paradox accepts this challenge and the Duel begins.

Paradox's Duel Runner  transforms into a flying type and he floats up high and the Duel begins.

Paradox declares the first move. He activates "Malefic World" that lets him put a random "Malefic" monster from his Deck to his hand instead of drawing a card during his Draw Phase. The field begins transforming into a purple atmosphere full of stars. Then, he sends "Cyber End Dragon" from his Extra Deck to the Graveyard to Special Summon "Malefic Cyber End Dragon" from his hand. He sets a card to end his turn (because in a 3-on-1 Duel, you cannot attack on the first turn). By this time, Yugi, Jaden and Yusei come to the realization why Paradox has been stealing monsters: He's using them to Summon the "Malefic" monsters, as Yugi understands that by destroying a monster's good version, Paradox can Summon their dark version.

Yusei tells everybody that despite them never fighting together before, they must work together to defeat Paradox, as Yugi & Jaden agree. Yugi then asks Yusei to take the first turn for his team.

Yusei activates "Reincarnation of Hope", which sends "Sonic Chick" and "Quillbolt Hedgehog" from his hand to the Graveyard; but on their team's second Standby Phase, they are allowed to add a monster from their Deck to their hand. Yusei then Summons "Junk Synchron" and due to its effect, he also Summons "Sonic Chick" back on his field. He then activates the effect of "Quillbolt Hedgehog" to Summon it back to his field. He then uses the 3 monsters to Synchro Summon "Junk Gardna" in Defense Position. Yugi becomes surprised by the concept of Synchro Summoning, as Jaden is just as confused by Yusei's Synchro card, but praises Yusei's play and shows his interest in the future cards. Yusei Sets 2 cards to end his turn.

Paradox adds "Malefic Rainbow Dragon" to his hand due to the effect of "Malefic World". He then sends "Rainbow Dragon" from his Deck to the Graveyard to Special Summon "Malefic Rainbow Dragon" from his hand. Jaden then becomes angry since Paradox is using Jesse's card. Paradox attacks "Junk Gardna" with "Malefic Rainbow Dragon", but Yusei activates the effect of "Junk Gardna" that switches "Malefic Rainbow Dragon" to Defense Position, thus stopping the attack. Paradox then attacks "Junk Gardna" with "Malefic Cyber End Dragon", this time destroying it and inflicting Piercing Damage to Yusei's Life Points. Yusei felt the real damage that Paradox did to him, but not before activating "Junk Gardna's" 2nd ability, which switches Paradox's other monster in Defense mode and "Miracle's Wake", reviving his "Junk Gardna". Yusei apologizes for losing some Life Points, but Yami and Jaden insisted that Yusei did a good job, stopping the assault of both monsters. Paradox then Sets a card and ends his turn.

As Jaden's turn begins (his theme song plays in the Japanese version), he asks Yusei if he may borrow "Junk Gardna". Yusei agrees, as Jaden activates "Polymerization", fusing his "Elemental HERO Neos" with Yusei's "Junk Gardna" to Fusion Summon "Elemental HERO Neos Knight". The ATK of "Elemental HERO Neos Knight" increases by half the ATK of "Junk Gardna", making it 3200. Because of the other effect of "Elemental HERO Neos Knight", it can attack twice during the same Battle Phase. Thus, Jaden attacks Paradox's "Malefic Rainbow Dragon" and "Malefic Cyber End Dragon" with "Elemental HERO Neos Knight". Paradox activates "Malefic Tune", allowing him to draw 2 cards. Jaden Sets four cards to end his turn.

Paradox adds "Malefic Stardust Dragon" to his hand due to the effect of "Malefic World". He then sends "Stardust Dragon" from his Extra Deck to the Graveyard to Summon "Malefic Stardust Dragon". Yusei then became shocked to see that his ace monster became corrupted and in the English dub he yells at Paradox, calling him a snake and is horrified at what has been done to his card. Paradox then Normal Summons "Malefic Parallel Gear" and tunes it with "Malefic Stardust Dragon" to Synchro Summon "Malefic Paradox Dragon". Yusei is stunned by this, to which Paradox says that he is not the only one who could Synchro Summon. He activates its effect, Special Summoning "Stardust Dragon" and decreasing the ATK of Jaden's "Elemental Hero Neos Knight" by 2500. Paradox attacks "Elemental HERO Neos Knight" with "Malefic Paradox Dragon", but Jaden activates "Hero Barrier", negating the attack. Yugi and Yusei praise Jaden for that move, but Paradox activates "Malefic Claw Stream", destroying "Elemental HERO Neos Knight", but Jaden activates "Elemental Mirage", resurrecting "Elemental HERO Neos Knight" with its original ATK (2500). He explains to Yugi and Yusei that he did this to ensure that there was at least a monster on the field by Yugi's turn. Because of the effect of "Malefic Paradox Dragon", the ATK of "Elemental HERO Neos Knight" is reduced to 0. Paradox Sets 2 cards to end his turn.

As Yugi's turn began (his theme song plays in the Japanese version), he adds "Dark Magician" to his hand due to Yusei's "Reincarnation of Hope". Paradox knew that he would try to go for the "Dark Magician". Yugi activates "Ancient Rules", which allows him to Special Summon it. The Dark Magician, however, is still affected by the effect of Malefic Paradox Dragon, reducing its ATK to zero. Jaden gets excited seeing Yugi's ace card, while Yusei remembers based on the archives, the Dark Magician is Yugi's ace monster. At this point, Yusei asks Yami to destroy Stardust Dragon, since Malefic Paradox Dragon's effect will prevent them from launching an attack. Yugi then activates "Bond Between Teacher and Student", which Summons "Dark Magician Girl" to his field. Yami then activates "Magic Gate of Miracles", which lets him take control of one of Paradox's monsters and which Paradox assumes it is his "Malefic Paradox Dragon". In response, Paradox chains "Malefic Force", which protects his "Malefic Paradox Dragon" from Yami's card effects. Yami then smiles claiming his true target is "Stardust Dragon". Now Yusei gets his "Stardust Dragon" back on his field. Jaden then praises Yami for this, noting that Yami never wanted Malefic Paradox Dragon in the first place. By doing so, Malefic Paradox Dragon's effect is negated, thus returning the Dark Magician & Elemental Hero Neos Knight's ATK to their original amount. Yami then activates "Dark Magic Twin Burst", combining his two monsters' ATK together, raising the ATK of "Dark Magician" to 4500. He attacks and destroys "Malefic Paradox Dragon", resulting in Paradox losing 500 Life Points. Paradox then grins, claiming that these desperate moves change nothing. Yugi disagrees, mentioning to Paradox that he had two monsters and now he has none. Paradox mentioned that they only created the path for the Summoning of a powerful monster and activates "Malefic Paradigm Shift", which Summons "Malefic Truth Dragon" to his field when his "Malefic Paradox Dragon" is destroyed. This costs Paradox half of his Life Points to activate (Paradox: 1750 Life Points). Paradox then fuses with his new monster and everyone is amazed to see such a gigantic monster. Yugi then Sets 2 cards face down and ends his turn.

By now, time has run out as Pegasus is about to arrive, but cannot land his helicopter due to Malefic World still being in play. Back in New Domino City, everybody is watching their dimension collapse but Jack knows that Yusei still has a chance.

Paradox then starts his turn. He plays "Malefic Selector" to remove "Malefic Parallel Gear" and "Malefic Cyber End Dragon" from play to add "Malefic Blue-Eyes White Dragon" and "Malefic Red-Eyes Black Dragon" to his hand. Paradox then sends both "Blue-Eyes White Dragon" and "Red-Eyes Black Dragon" from his Deck to the Graveyard to Summon "Malefic Blue-Eyes White Dragon" and "Malefic Red-Eyes Black Dragon".

Yugi is shocked that the "Red Eyes Black Dragon" & "Blue Eyes White Dragon" have become Malefic monsters as well. Paradox then attacks "Dark Magician Girl" with "Malefic Red-Eyes Black Dragon". At that point, he also mentions Malefic Truth Dragon's ability: If a Malefic monster destroys one monster, the other monsters are destroyed also. Jaden then activates Yugi's "De-Fusion", sending Elemental HERO Neos Knight back to the Extra Deck and Summoning his "Elemental HERO Neos" and Yusei's "Junk Gardna". Yusei then uses the effect of "Junk Gardna" to switch "Malefic Red-Eyes Black Dragon" to Defense Position, thus canceling its attack. Yugi praises both Jaden and Yusei for this impressive display of teamwork but then Paradox then attacks "Dark Magician" with "Blue Eyes White Dragon" and destroys it, costing Yugi, Yusei and Jaden 500 Life Points. He then activates the effect of "Malefic Truth Dragon" which would destroy all of Yami, Jaden and Yusei's monsters, but Yusei activates the effect of "Stardust Dragon" to negate the destruction effect of "Malefic Truth Dragon" and destroy it. However, Paradox activates the effect of "Malefic Truth Dragon" which removes from play his "Malefic Rainbow Dragon" and negates the effect of "Stardust Dragon". He then attacks "Elemental HERO Neos" with "Malefic Truth Dragon" and thus activating its effect again, destroying "Dark Magician Girl" and "Junk Gardna". Also, for every monster destroyed, Malefic Truth Dragon inflicts 800 damage. Yami, Jaden and Yusei's Life Points are all reduced to 500 as all 3 of them are pushed back by the explosion. Paradox then activates "Malefic Divide", Special Summoning "Malefic Stardust Dragon" from the Graveyard. He then orders it to unleash its fury so that Duel Monsters will perish forever. Yusei falls to his knees, saying that everything is lost and the future is doomed. Jaden tells Yusei not to surrender reminding him that they have a "secret weapon" on their side. Yugi also tells Yusei that other than Paradox, they believe in Duel Monsters. To show him what he means, Jaden activates "The Flute of Summoning Kuriboh". The effect of "Flute of Summoning Kuriboh" allows Yami to add "Kuriboh" to his hand. Yami then discards "Kuriboh" to reduce the Battle Damage to 0. Paradox ends his turn, but not before "Malefic Stardust Dragon" gets destroyed by the effect of "Malefic Divide" and the original "Stardust Dragon" gets Summoned back to Yusei's field due to its ability. Yami then tells Yusei that no matter which era he is in, his friends will always be supporting him.

Yusei gets up, as Yami & Jaden tell Yusei to end the Duel, as they promise to aid. Yusei activates "Stardust Mirage", Special Summoning all monsters that Paradox destroyed during this turn. This brings back "Dark Magician Girl", "Dark Magician", "Elemental HERO Neos" and "Junk Gardna". Paradox is shocked, as all the monsters previously destroyed in his turn are Special Summoned back to their field. Yusei then draws a card to start his turn, as Jaden then activates "Neos Spiral Force", doubling the ATK of "Stardust Dragon" to 5000. Yami then activates "Dark Spiral Force". This then doubled Stardust Dragon's attack again to 10000. Yusei attacks "Malefic Truth Dragon" with "Stardust Dragon" and the combined efforts of "Dark Magician" and "Elemental HERO Neos", winning the Duel and restoring peace. Paradox is destroyed by the attack and is never to be seen again. Pegasus is finally able to land and arrive at the event.

After the Duel, Yusei thanks Jaden and Yami Yugi and hopes to meet them again. As Yami Yugi looks down from the rooftop towards the event where Pegasus is among the crowd. Yami Yugi gives a friendship speech and Yusei and Jaden return to their respective timelines. Back at New Domino City, everybody comes running to Yusei as Yusei himself looks at the sky and hopes to protect his future so that one day, he can meet Jaden and Yugi Muto/Yami Yugi again. In the English version, he also says that the true magic of Duel Monsters isn't in the cards, it's the bonds we forge because of it.

Leo
Leo and Luna share a very close bond with one another. Leo is the only one so far to be able to reach out to Luna in the Spirit World, the first time doing it when she was 3 and in a coma in the real world. Leo believed she could still hear him that time, and woke up. When Luna was brought back to the Spirit world in the present, she didn't feel confident enough to protect it, but Leo vowed to protect her, while she protected it, and as a result she resumed her promise. They also look out for each other and help one another, as shown when Leo takes Luna's place Dueling Devack while she was in the Spirit World, and then does what she can after taking over for him. Luna has shown quite a few times that without Leo to support her, she'd be lost, and has even referred to him as her 'hero'. Their bond runs so deep that when her brother died against Aporia, she screamed in misery and also began losing Life Points through a weakened heart pulse. As Life Points were tied to the Duelist's actual life, it is proven with this that she would literally die without her brother.

When her brother was blown off the circut, and was saved, Luna put a hand on her heart thinking "But what was that, that feeling I felt from my heart?" (the english version drastically changed her words to "Thank goodness for the Crimson Dragon, he'll always save the day").

After Leo awakened as a Signer, Luna cried tears of joy, saying he would always protect her, and calling him her hero while looking at him adoringly. As the gang prepared to part ways, Luna comments on how much Leo has changed, stating that he's more of a man now, and referring to him as "big brother".

Yusei Fudo
Yusei has an older brother-younger sibling relationship with the twins. She was initially wary of him because of his criminal mark, and his status as an escapee from Satellite. The twins eventually warm up to him, and support him. After Luna woke up from her hypnosis by ending the Duel with Professor Frank. She collapsed, and Yusei carried her away from the Dueling platform. Yusei also showed concern for her during her Fortune Cup Duel. When she woke up after the fight with Frank and got out of Yusei's arms, she replied she was okay, and Yusei told her to simply do what she wanted in a kind voice.

Akiza Izinski
At first Luna seemed to have a cold feeling about Akiza. This was first shown when Akiza was Dueling in the Fortune Cup. Luna would state how she felt about Akiza's cards & how Akiza behaved. But she seemed to care for Akiza & thought that she was misunderstood. This is shown when she looks in disgust at the jeering fans who are cursing Akiza for being a witch. After Akiza develops a bond with the Signers, Luna seems to look up to her as an older sister figure, calling her "Aki-san". Her bond with Akiza also seems to have gone to her Deck when in season 2, she starts using Bird of Roses, Nettles and Spore.

Jack Atlas
Although not as clear as her brother, Luna does seem to hold some respect for Jack Atlas. Through the battle with Aporia, it is also evident that Jack to some degree worries for Luna, as her heart weakens, he angrily curses at Aporia for harming such a small child.

Ancident Fairy Dragon
The ruler of the Spirit World found Luna's spirit when she lapsed into a coma. Until she woke up, Ancident Fairy Dragon watched over her as if she was Luna's guardian angel. Luna vowed to protect the spirit world, but had to forsake that promise. She resumed keeping that promise after her Duel with Professor Frank. After Leo's Duel against Sayer, she turned to her for help. When she finally set her free during the Duel with Devack, she thanked Luna for keeping her promise and is currently by her side as a Synchro Monster in her Deck.

Patty
Patty is Luna's friend, usually seen hanging around her.

Lester
Luna was shown signs of having a small crush on Lester when he first enrolled at the Duel Academy as a normal student (this include her blushing and looking away flustered when Lester first smiled at her. Her crush on him is further evident, as Yusei pointed out with a slight smile that it was odd for someone like her to be giving someone so much praise like that). However it was proven to be short-lived, because after Luna found out that Lester was the one hurting them, she displayed anger, and some hatred, and even said after Lester almost killed Leo right in-front of her "Who'd be defeated by the likes of you!"

Knownable Relatives

 * Leo (older twin brother)
 * Yusei Fudo (Surrogate older brother)
 * Akiza Izinski (Surrogate older sister)
 * Jack Atlas (Surrogate father)
 * Yugi Muto/Yami Yugi (counterpart)

Trivia

 * The Japanese names of the twins to be Rua and Ruka. However when their names appeared wrote out in the Japanese anime, they were Lua and Luca. The differing names is due to Japanese speakers pronouncing "L" and "R" as the same sound. When they Dueled against Lester and Aporia in the Japanese version their names were written as Lua and Luca
 * The 4Kids Entertainment website listed Luca's English name as Luna in the characters page, while Lua had his changed to Luka. Luka later had his name changed to Leo, while Luna's stayed as Luna.
 * The Russian word Ruka, or Рука, means hand or arm.
 * Luna's Japanese name, Ruka means "bright blue flower". Luna is an Italian name of Latin origin meaning "moon".

Voice Actresses
Japanese : Yuka Terasaki

English : Cassandra Morris (episode 12 - episode 64), Eileen Stevens  (episode 65 - present)