Leo

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 * For Zora's son, see: Leo (son).

Leo, known as Rua or Lua in the Japanese version (see below), is Luna's twin brother. He and Luna aid Yusei Fudo, whom they admire and support, in his duels. Leo is the older twin of the two and has a lively and blundering personality.

Personality
Leo is a lively and carefree character, but has been shown to take things seriously when the situation calls for it. Occasionally he will doubt his skill but his sister Luna always looks towards him for encouragement.

Design
Leo's outfit is similar to his sister's; it consists of a short-sleeved light blue jacket over a sleeveless dark blue shirt with golden markings that differ from Luna's shirt. He also wears light blue shorts with a dark blue belt and blue sneakers of the same color. Leo also has a bracelet on each wrist, and his blue-green hair is pulled into a single, high ponytail with two shoulder-length bangs on both sides of his face but when he doesn't wear it up (like when he's sleeping) it looks like Luna's in the same situation. He carries a Duel Disk with a blue and white trim on his left arm, which was originally too big to fit until Yusei modified it. On formal occasions, he wears a blue suit with a white shirt and blue bowtie under the jacket, and black loafers with white, knee-high socks. When he's sleeping, he wears light blue pajamas. If at school, he wears the New Domino academy boys uniform with a green book-bag.

Biography
Leo lives together with Luna in the Tops residential area. They spend most of their time alone together as their parents are usually at work. They are educated via the internet, so they spend most of their time inside. Later, both he and his sister attend Duel Academy.

Fortune Cup
Luna was able to sense Yusei when he was shocked by the police officers, so she and Leo rescue him after his Duel with Trudge and took him to their home. Yusei wanted to leave, fearing he may place them in danger, but Leo talks him into a Duel. After Yusei wins, they manage to persuade him to stay for the night. (In the English dub, Yusei had lost his memory and dueled Leo to help him remember.) Leo and Luna awaken the next morning to find that Yusei had left after modifying their Duel Disks to fit their small arms. Leo then leaves with Dexter to find and duel the Black Rose. They eventually meet up with Yusei again, and shortly afterward the Black Rose appears, but leaves after seeing Yusei's Mark of the Dragon, which seems to disgust her. Leo shows fear for both the Black Rose and the Mark. Luna was selected as someone to participate in the Fortune Cup, but because she didn't feel like participating, Leo planned to disguise himself as her and compete instead, and Luna adds the saying "Leo wears makeup!". The next day, Leo enters the Fortune Cup in disguise as Luna, but quickly loses to Greiger after a hard-fought Duel. Using Zigzix's Signer-detecting technology, Lazar determines that Greiger dueled Leo instead of Luna. During the consolation Duel where Luna dueled Professor Frank, Leo was hypnotized along with his sister and later reveals to her that he had unconsciously given himself the task of protecting her while she protects the Duel Monsters Spirit World. He was awakened from his trance when the Duel ended. At the end of the first day of the Fortune Cup, it is shown that Yusei would be paired against Greiger the next day. As Bolt Tanner wondered what kind of Duel Runner Greiger had, Leo tried to find out and ran off. He snuck into Greiger's garage, and got frightened by the look of Greiger's Duel Runner. His scream triggered a security alarm, locking him in the garage, where he slept until Greiger returned and found him sleeping.

Dark Signers
At the end of the Fortune Cup, Leo, along with his sister, learns what a Signer is. He is worried about Yusei going by himself to Satellite after what the Dark Signer said. After Yusei's Duel with Kalin Kessler, Tanner and Yanagi arrive at their home as they discuss the current situation. They are worried about whether Yusei had already fought against a Dark Signer or not. Then he asks Luna if it's true that "Power Tool Dragon" battled alongside the other Five Dragons against the Earthbound Immortals, to which she responds that it may have. Leo immediately assumes himself to be the Fifth Signer and proclaims that he must also protect Luna as well. Yanagi reasks and Luna says she only said yes to cheer up Leo In order for all the Signers to work together to fight the Dark Signers, Leo proposes that they seek help from Akiza. As they accept, he learns about the Arcadia Movement. Leo along with Luna, Bolt, and Yanagi, then go in search of Akiza. Upon reaching the Arcadia Movement base, they are tricked by Sayer. Leo then wakes up chained, and is made to Duel Sayer as a test in order to determine if he possesses any sort of ability, since he is Luna's twin brother. Leo also learns that Sayer plans to use his psychic duelists as soldiers in a war against the world for all the discrimination they have taken. As the Duel progresses, Sayer attacks Leo directly, making him cry, however he tells him not cry and instead fight. Due to the fact that he has revealed his true purpose, Leo's life is at stake now, and in order to save himself, he must awaken his hidden abilities. Despite his determination after Summoning "Power Tool Dragon", the Duel ends in Sayer's victory. Leo then falls to the floor and passes out. He is later seen on a bed, with Luna watching over him. He and Luna are then rescued by Tanner and Yanagi, and before being able to leave the building they all witnesses the duel between Akiza and Misty Tredwell. After the building begins to collapse due to the Earthbound Immortals' assault on it, Tanner takes the two of them outside to safety. After Akiza lands in the hospital in a comatose state, Leo, along with Luna, as well as Jack are present within. As with the rest of the people there, he witnesses the duel between Yusei and Akiza. After it concludes with Yusei's victory, Leo tags along with Luna and the other Signers as they are invited by Rex Goodwin into his place, as he wants to reveals to them some secret concerning the Crimson Dragon, as well as some sort of deep connection between them and the Dark Signers. There he learns about their own "fate" which is responsible as for that the Signers to have met in someway. Leo finally learns that the Fifth Signer was already awakened long ago and that it will appear later on, and also about the Dark Signer's true identity involving the Underworld, their abilities, and use of Earthbound Immortals.

After that Leo seems to accept the fact that he is not a Signer, he tells Luna that then there's no reason for him to go with them to Satellite, as the only thing he could if he did is to get in their way. However his sister tells him that he doesn't need to be a hero, just to be there to protect her as he promised from the start, that being the reason of why he accompanies her and the other Signers to Satellite. Akiza, Leo, and Luna eventually meet up with Yusei and Jack, giving Yusei a morale boost and support so he will hopefully change his mind about refusing to duel Kalin by saying that they will all fight along his side. Yusei and Jack both have friends to fight for, along with the protection of Satellite and New Domino City. An argument between Jack and Leo breaks out, as Leo says that he will definitely become cool like Yusei and Jack, but Jack insists that Leo will never become cool. Afterwards, the Dark Signers perform some kind of dark ritual within Satellite, not only enclouding but also somehow vanquishing its other Satellite residents. Because of this, the Signers, along with Leo and Mina, all board a helicopter to Satellite being flown by Trudge himself. When they all arrive to Satellite they are greeted by Martha. However, the reunion is cut short as Yusei finds out that Rally, Crow, and the others have disappeared. Later during dinner, Roman suddenly appears, demanding to Duel. As Yusei accepts to Duel, accompanied by Akiza, Jack and everyone else take Martha and the kids to a safer place. As Roman and Yusei's Shadow Duel is about to begin, Luna, Leo, and Jack become aware of it as their Marks of the Dragon began to react. After Yusei's match against Roman concludes, Jack, Akiza, and Luna, along with Leo, are present as the rest of the Dark Signers reveal themselves. 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. Despite Devack's warning that Leo isn't a Signer, and therefore he won't be able to beat him, the Duel begins and Devack is able to quickly inflict damage to him. However, Leo counterattacks by Synchro Summoning "Power Tool Dragon", his ace card. Devack then unleashes his Dark Synchro Monster, "Zeman the Ape King". Leo, after getting a strategy together, is able to push Devack back by destroying "Zeman the Ape King". He gets backed into a corner again when Devack summons "Earthbound Immortal Cusillu". After Luna comes back, she sees her brother in trouble and takes over for Leo as a way of making it up to him. She and Leo then win the Duel together. After Crow's Shadow Turbo Duel against Greiger ends, Leo, along with Luna, and Trudge are all currently witnessing the rematch between Yusei and Kalin. After the extreme Duel between the 2 finally ends, Leo, Luna, 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. He watches the Duel between Yusei and Roman with Yusei winning. He watches in horror as Roman blows up the bridge and drops Yusei into the Ener-D Reactor. Leo at first believes that he is dead, but, like everyone else there, is surprised when Yusei returns, though unconscious. And after he wakes up and that everyone eventually go up through the same stairs they use before, they all notice in the distant the purple sparks, to which they can only believe means that Jack has won and also activated the third Tower. Knowing that the last Tower to be activated is Akiza´s task, Leo, Luna, Trudge, and Yusei all go to where it is. Arriving at and old and abandoned carnival the twins began looking for her and Mina. After Sayer awakens Akiza's power and is transformed once again into the Black Rose, they notice the tornado that has materialized after she summons "Black Rose Dragon". As they then 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. They then see the Condor geoglyph that has appeared on the sky. The King of the Underworld not only revives, but also is heading towards the formed Condor geoglyph, which is over New Domino City. However, the Crimson Dragon appears once again to take everyone to Rex Goodwin's mansion. Where he reveals to them his identity as the final Dark Signer and then declares that a Shadow Turbo Duel will be held within Condor geoglyph as a ritual to welcome the King of the Underworld. As Yusei, Jack, and Crow accept the Duel in order to stop the resurrection of the King of the Underworld, Leo cheers for them along with his sister and the rest of the people who can only support them by watching while hoping they win.

World Riding Grand Prix
Leo has enlisted into the New Domino City Duel Academy along with Luna. Dexter also accompanies them as the 3 of them are pupils there of Miss Bartlet. Long after that Leo, Luna, and Dexter go to a haunted forest were people are reported to disappear. Soon after they venture into the forest, Luna disappears. Leo then goes looking for her while Dexter goes to get Yusei. Leo finds a mansion and sees Luna in a window. A boy then appears, preventing Leo from entering. Leo duels the boy, whose name is Haley, as Haley believes that Leo is there to hurt his sister. When Yusei arrives, Leo asks Yusei to help Luna and leave him fighting Haley. Yusei gets in and assists Luna. Luna wants to help the spirit of Clare, who is still in the house, and finds a special card. Leo defeats Haley, whom he finds out is just a spirit, and Luna is free. Luna gives Haley the special card and Haley and Clare disappear. Leo and the gang appear at the Riding World Grand Prix premiere. Leo and Luna watch Akiza on her first day of riding a Duel Runner. After the lesson, the two accompany Yusei and Akiza to a skating rink so Yusei can show Akiza a few tricks. He comments that this is a date to his sister and Luna agrees at some point. When Lester enters Duel Academy, Leo gets very suspicious about him and tries to protect his sister from him. Lester does all he can so he can keep him separated from Luna. While stuck at school, later knowing it was a trick, he sets out to find Lester's mansion and discovers he Duels using a skateboard for riding duels. After finding this out he asks Yusei to construct a similar device in order to challenge Lester. Yusei constructs a dueling skateboard dubbed a Duel Board for Leo. He tries to gain some experience riding it, though he has difficulty at first. He then meets up with his sister, who is also trying to practice with the board Lester gave her. However, the skateboard Luna receives is controlled by Lester and forces her to duel him. Leo then joins the Duel to protect his sister. During the Duel, Leo identifies the mysterious duelist as Lester. Luna quickly summons "Ancient Fairy Dragon", but loses it to "Machine Emperor Skiel Infinity" and things begin looking grim. Leo summons "Power Tool Dragon" to try and turn the duel around, but Lester upgrades "Skiel Attack" and its ability attacks him directly. Despite the fact that Leo could not defeat Lester, Leo did succeed in making Lester so mad that he rushed to finish the duel without capturing Luna's "Ancient Fairy Dragon", his likely goal all along. Leo is blown off the track and falls, only to be saved by the Crimson Dragon. The Dragon's sudden appearance surprises everyone, even their mysterious spectators. After the Duel, the twins backtrack where Lester lived, only to find an empty space. No one else in Duel Academy seems to recall him either. Leo appears during the beginning of the WRGP as a part of Team 5D's pit crew.

Luna
Leo and his sister are known to be together in almost every scene of the show (not including the Fortune Cup) and have an extremely close bond. Throughout the entire show, it is made apparent that in every situation involving Luna, Leo is the one to give her the strength to fight back. Even though Leo appears to be completely ordinary, when his sister goes to the spirit world, he is somehow able to communicate with her. It is said that when Luna went into a coma state when she was 3, Leo was the only one that believed she would awaken, and was said to be the one that awoke her from the spirit world. So far, only Leo has been able to awaken Luna when she goes to the spirit world. Luna is the most important person in his life and he will protect her at any cost from dangers; to Luna, Leo is her 'hero' and she can't live without him. The possibility for Leo being the only one to awake her from the spirit world is because he might have some of the abilities that she possesses. It is a known fact that Leo and Luna go together to Duel Academy along with Dexter and their teacher Miss Bartlet. Even though the twins have their ups and downs they love each other dearly and are considered the most valuable person in the other's life. When they were battling Devack and his Earthbound Immortal he said he wanted to show that he can protect his sister from harms way including from Devack and Luna tells Devak she will never forgive him hurting the person she cares about most in the whole world. He also feels that he is useless and can't protect her from harm but Luna says she needs him. In the original he said she was a bother to him while in the English dub he said she was holding him back.

Yusei Fudo
Yusei Fudo is shown to be like a brother-figure to both Leo and Luna. Leo is shown to look up to Yusei as the best duelist ever. Yusei has given Leo many tips when it comes to dueling and has inspired Leo to become even better. This is seen after Leo faces against Devack, to which during the duel Yusei notices that Leo is dueling more carefully, realizing that he has changed and grown up since their first duel. Because of this, after the duel ends, Yusei congratulates and tells Leo that he did well.

Jack Atlas
In episode 13, Leo is shown to admire Jack Atlas from the time the latter reigned as King. He has figurines of Jack and his "Red Dragon Archfiend", but now thinks of Yusei as the better Duelist after the Fortune Cup, much to Jack's annoyance. Even if he does, Leo was inspired by Jack to become a great Duelist.

Akiza Izinski
Leo looks up to Akiza Izinski as a Duelist, even when she went under her alias, the "Black Rose Witch". Although he was somewhat scared of her, he still admired her abilities. He wants to be ranked at the top of his class like she is. He also relied on her to stand up for their right to duel in Duel Academy.

Naming
Linework by Kazuki Takahashi has revealed 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 in names are due to Japanese speakers pronouncing "L" and "R" as the same sound. When he dueled Haley in the Japanese anime, his name was spelled Rua. When the twins dueled Lucciano their names were spelled Lua and Luca. The 4Kids Entertainment website initially listed the twins in the character section. Here Lua has his name changed to Luka, while Luca has hers changed to Luna. Both characters have since been removed from that section of the website. His name was changed to Leo, short for Leonard, when he appeared in the English anime.

Deck
Leo plays a Morphtronic Deck that features an Archetype of monsters known as "Morphtronics" whose effects are dictated by battle position. The monsters' appearances are derived from various objects such as cell phones, pen drives, cameras and magnets. His Deck also specializes in summoning his strongest card, "Power Tool Dragon", and the use of Equip Spell Cards. In Yu-Gi-Oh! 5D's World Championship 2009: Stardust Accelerator, he uses a Deck called "Transform, ta-da!" This focuses on his Morphtronic Monsters, and also on Cyber Dragon and his two Chimeratech dragons. His Tag Force 4 Deck again focuses on his Morphtronic monsters, but they serve as disruption until summoning Power Tool Dragon and using its effect. During the 3rd Arc of the Series, at the Duel Academy, he uses Swordsman of Landstar (or possibly Comrade Swordsman of Landstar) and Marauding Captain. Though it is known that Leo was only using them at the time because the lesson is based on Warrior-Type monsters. So, like Dexter, their Decks were revolving around this type of monsters for practice only. In season 2, like his sister, Leo has a Deck for Turbo Duels as well.