Leo

Leo very short for Leonard, while aka Rua or Lua in the Japanese version. He is a character in Yu-Gi-Oh 5Ds. He is Luna's twin brother, and was one of the Signers who possessed the Heart Mark of the Dragon. Including the only other Signer aside from Yusei, who has been able to weaken the "Meklord Emperors". He and Luna aid Yusei Fudo, who they admire and support, in his Duels. Leo is the older twin of the two but has a lively, and blundering personality.

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

Personality
Leo is seen as a lively and blundering character (in the English version he is very carefree and acts dumbly), but is shown to get very serious when the situation calls for it. Occasionally he will doubt his skills but his sister Luna always look towards him for encouragement. He started off as cocky and sure of himself, but became more mature and careful as the series progressed.

He is also shown to be very perceptive in season 3, as he immediately felt something was not right about Lester even when he had not acted suspicious just yet.

In the manga, while being under the influence of the miasma of "Power Tool Mecha Dragon", Leo is quite sadistic. This is shown when he enjoyed crushing D1 Grand Prix Duelists with his, and Luna's Duel Dragons or when he sat back and watched as two bystanders were almost killed by a stray missile fired by his Duel Dragon during a Duel. Although this is said, Leo has a soft side, especially when Luna is involved and he will do anything to help her (as shown with his participation in Turbo Duels in order to raise funds to pay for her medicine). Leo also often gets into arguments with Luna over her teasing him or with Crow Hogan who usually mocks Leo for his size.

Appearance
Leo's outfit is very similar to his sister's; it consists of a short sleeved white jacket over a sleeveless dark blue shirt with golden markings that differ from Luna's shirt. He also wears white 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.

In the manga, Leo's outfit is similar to his sister's; it consists of a short-sleeved white jacket over a sleeveless dark blue shirt with golden markings that differ from Luna's shirt. He also wears white 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. Whilst controlled by the miasma of "Power Tool Mecha Dragon", he often displays an evil expression on his face. After his first Duel with Yusei, Leo's face features a bandage as he sustained an injury.

Yu-Gi-Oh! 5D's Manga
Both Leo and Luna were left to fend for themselves at a young age. In order to acquire money, the pair began to compete in Turdo 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 beat up 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. Luna later underwent the same ceremony, acquiring "Ancient Pixie Dragon".

During the second round of the D1 Grand Prix, Mina Simington reported to Rex Goodwin that the semi finalists were being attacked by Leo and Luna. Leo boasts about how if he defeats Aria, it'll be his 5th victory that day and that the D1 Grand Prix contestants are weak. Luna agrees with him, stating that they're even weaker than he is. Leo then proceeds to attack Aria, winning. During the assault, one of "Power Tool Mecha Dragon's" screwdriver missles almost kills two bystanders, but Crow intercepts it with his Blackwing Tamer-Hawk Joe the Jet Black. He then scolds Leo, who says he'll target Crow next. Later on, Goodwin informs the remaining contestants that he's dispatched Leo and Luna in the tournament as only the best should remain.

Leo later appears before Yusei and Crow, the both of them mistake him for Sect but Leo scolds them for getting his identity mixed up with someone else. Crow mocks Leo and his sister, saying that they should be in bed as its late, but Leo mocks Crow back, calling him a "broom-head". Leo then proposes a Duel to Yusei, showing him his Duel Dragon, causing a Shadow Miasma to pulse from the card. Both Crow and Yusei feel it, surprising Luna. Leo also reveals that Goodwin is involved with the Duel Dragons to Yusei. During the Duel, Luna tells Leo that if any of her Forest Archetype monsters are destroyed, she'll make Leo pay. Leo then manages to Synchro Summon his "Power Tool Mecha Dragon".

Leo continues his assault, managing to power up his "Power Tool Mecha Dragon" with his Equip Spell Card strategy. Yusei manages to Synchro Summon Seven Sword Warrior in order to conduct an Equip battle with Leo, but his "Duel Dragon" steals Yusei's Equip Spell Cards. Yusei then uses Sword Dance which fires several solid vision swords at Leo and Luna, one of which hits Luna. This causes Leo's anger to increase, making the Duel Dragon's Miasma intensify. Leo then fills his entire field with "Forest" monsters with cards to power up his "Power Tool Mecha Dragon" to 4800 ATK. It then beheads "Seven Swords Warrior", causing Yusei to lose 2500 Life Points with Leo telling Yusei that the Duel belongs to him.

Yusei notices that Leo has someone to protect like he does and the spirit of a turbo duelist that can't give up for that person's sake. Leo yells that Yusei should't act like he knows as he was the one who hurt Luna in the first place. Leo starts to become more angry then he was before, causing his shadow miasma to become larger. Yusei activates his trap Synche Nova to exculde six cards in his Graveyard and Speical Summon Gravity Warrior. Using both of its effects, Yusei defeats Leo. As Yusei's sense was about to hit the twins, Leo protects Luna and shields her from the attack. Leo appears heavily injured from the attack and says to Yusei that things will be different in the second stage. When Luna threatens to make Yusei pay for hurting Leo, he calms her down and assures that although they lost, they did what they came to do and afterwards they both leave.

On the boat heading to Satellite, Leo and his sister were enjoying a meal but Leo gets into a fight with Crow when he makes fun of him for losing to Yusei.

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.

Leo and Luna wait for Yusei at the 6th Duel Zodiac, having been told he will be there by Goodwin. As soon as he arrives they begin their second Duel. In the Duel Luna orders Leo to Summon her Duel Dragon, "Ancient Pixie Dragon" but instead he Summons his "Power Tool Mecha Dragon". Luna begins to sulk over this but Leo assures her that he has a plan. Unbeknownst to Luna, Leo plans to end the Duel early without Summoning "Ancient Pixie Dragon" as he believes it is dangerous to Summon it. Both of them become surprised when Yusei Synchro Summons his "Stardust Spark Dragon" for the first time.[9]

When Yusei's "Stardust Spark Dragon" destroys Leo's "Power Tool Mecha Dragon", its destruction frees Leo from its shadow miasma. Leo reveals that Rex Goodwin was the one who ordered them to Duel Yusei in the first place as Leo believed by doing so would turn Luna back to normal. However Luna overhears this and uses her shadow miasma to brainwash Leo. In this state Leo no longer speaks and simply draws cards for his sister. However for one brief moment Leo is able to active a trap on his own much to his sister and Yusei's surprise. Upon seeing this, Yusei calls out to Leo in order to snap him out of Luna's control. While it didn't work at first Yusei keeps at it and succeeds in awakening Leo. This angers Luna and causes her to become completely controlled by her Duel Dragon's shadow miasma. Using "Stardust Spark Dragon along with two Quick-Play Spell Cards allows Yusei to defeat the twins and free Luna from her shadow miasma.[10]

After being defeated the twins thank Yusei for saving them. Leo tries to warn Yusei not to enter the Duel Gate as there is a ritual going on there and that it is dangerous. While he knows it is dangerous Yusei tells Leo he still must go as he has someone he wishs to protect just like Leo does with Luna. After watching Yusei leave, Leo is still worried for him but his sister assures him that Yusei will be fine as he was the one who saved them to which Leo agrees with. Afterwards they retire from the tournament.[11]

Leo along with his sister enter the Duel Gate looking for Yusei.[12] Leo finds himself becoming weak after Goodwin begins to absorb the energy from the Duelists in the Duel Gate and is surprised to see his "Power Tool Mecha Dragon" card and the rest of his Deck become blank.[13]

Leo would lend his support to Yusei when the latter faces the Ultimate God by praying to him[14] and later by sending his Sense to him alongside the other Duel Dragon holders.[15] When the Uchatsui Miime start attacking everyone in the Duel Gate, Leo grabs a pole from the ground to fend them off while protecting his sister.[16] One year later Leo and his sister proceed to watch the final match of the second D1GP between Yusei and Jack.

Fortune Cup arc
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 version, 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 arc
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 Signer 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 re-asks 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 Immortal's 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 Netherworld, 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 fulfil 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 it's 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 Netherworld 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 Netherworld.

As Yusei, Jack, and Crow accept the Duel in order to stop the resurrection of the King of the Netherworld, 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 Racing Grand Prix arc
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 Claire, 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 Claire 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. Despite the fact that the Duel was one in which damage was real, Lester brushed off Luna's attack, but for some reason Leo seemed able to hurt Lester (it is not known why though).

Leo appears during the beginning of the WRGP as a part of Team 5D's pit crew.

During Yusei's Duel with Aporia, Leo, along with the rest of the team, is shown a vision of the future, which leaves him in disbelief, but not to the point where he gives up on the future they're creating. After hearing from Sherry LeBlanc that Yusei will die if he enters Divine Temple, Leo breaks down into tears, questioning if it's really worth it for Yusei to risk his life. He then cries out that he doesn't want Yusei to die, but Yusei reassures the boy that he won't.

Ark Cradle arc
Leo and everyone else on the team accompany Yusei to Divine Temple. After they are split into three groups due to Z-one's trickery, Leo travels with Luna and Jack to the center of the structure unaware that Aporia would be waiting for them at the second gear fully repaired. He is then forced into a 3 on 1 Duel with Jack and Luna with their life on the line. Despite his attempts to power up "Red Dragon Archfiend" and protect Luna's Life Points, his strategy backfires after Aporia Summons "Machine Imperial Soldier Grannel Ein" and knocks out both of his partners, destroying Jack's Ace monster. Aporia then declares by the current situation that Leo would have to continue alone against him after he ends his turn.

Leo, in his efforts to protect Luna, manages to Special Summon "Power Tool Dragon" and "Ancient Fairy Dragon" which, ultimately, leads to his death. However, he is revived due to the effect of his "Morphtronic Lantron" and the power of the Crimson Dragon, obtaining the Heart Mark of the Dragon, making him the sixth Signer. Finally he Synchro Summons "Life Stream Dragon", and is able to restore Luna's, Jack's, and his own life points due to its effect (their wounds were also healed, but it is currently unknown why). When he attacks Aporia during this turn, it marks the only time in the Duel that Aporia appeared to be physically affected by taking damage (for unexplained reasons). They finally defeat Aporia by reducing Aporia's strongest monster's ATK.

After meeting up with the whole team, they venture deeper into Divine Temple and finally find it's main inhabitant. The team is surprised when Aporia who was presumed dead reappears and initiates a Duel with Z-one, aiming to remind him of hope. Even though he manages to summon the three Meklord Emperors, they are of no use against Z-one's Time Lords and eventually he is defeated. Realizing the power of Z-one's Deck, and following the example of Jack, Crow and Akiza, along with his sister, Leo gives Yusei his "Power Tool Dragon" and his "Life Stream Dragon", hoping to aid him in the last battle.

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. Leo and his sister are unable to decide what to do because they want to stay with the gang. After Jack challenges Yusei to a Duel which he agrees, the twins along with Akiza and Crow watch the Duel. They ultimately decide to go with their parents, and years later, Leo would become a professional Turbo Duelist.

Video Games
Leo is a playable character in the following video games:
 * Yu-Gi-Oh! Decade Duels
 * Yu-Gi-Oh! Duel Links
 * Yu-Gi-Oh! Duel Terminal
 * Yu-Gi-Oh! Duel Transer
 * Yu-Gi-Oh! Legacy of the Duelist Link Evolution
 * Yu-Gi-Oh! Online
 * Yu-Gi-Oh! Wheelie Breakers
 * Yu-Gi-Oh! World Championship
 * Yu-Gi-Oh! 5D's Tag Force

Luna
Leo and his sister are known to be together in almost every scene of the show (not included in 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. 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 Devack 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. In the Duel with Aporia, after Luna got knocked out from Machine Imperial Soldier Grannel Ein, it had a devastating effect on him similar to the first of Aporia's embodiment of despair Lester had his parents lost. This Duel further affects him in his confidence of protecting Luna, while at several parts of the Duel Aporia counters all of Leo's moves leaving both Jack and Luna close to death. This makes him to force himself to be stronger and literally put his life at risk to protect Luna, best demonstrated by using Double Ripple to summon Ancient Fairy Dragon for Luna, which costs him his life (for a brief moment) and was reborn as the Sixth Signer with Life Stream Dragon.

Leo has shown strong protectiveness and jealousy when someone flirts with his sister, or when she shows romantic interest in someone (particularly in the Japanese version). After the fight with Z-one, Leo blushes upon seeing Luna in new clothes, commenting on them while turning away and smiling (and being noticeably flustered).

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.

Akiza Izinski
Leo looks up to Akiza Izinski as a Duelist, even when she went under her alias, the "Black Rose". 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 the Duel Academy. He often refers to her as "Big Sister Aki", and has great respect and love for her like a sibling. (Japanese version only).

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. During the Duel against Aporia, Jack notices something new about Leo and said that Leo would protect anyone at any cost even if it means giving up his life. Although not seen too much, Jack has shown concern for Leo, like a surrogate father/older brother to him, and tells Leo to never give up fighting (which occurs when Aporia tries to get Leo to give up, and when Leo dies from Aporia's attack for a moment).

Bob and Dexter
Bob and Dexter are Leo's friends, as he is seen to hang out with them at Duel academy (and has known Dexter before he met Yusei).

Aporia
Like the other members of team 5D's, he saw Aporia as an enemy. During the Duel in the Ark Cradle, Aporia constantly caused Leo to feel despair by attacking Jack and Luna, but instead, Leo responded by fighting bravely and died for a moment, but then was revived as a Signer, and with Jack and Luna, he shows Aporia hope. During Aporia's Duel against Z-ONE, Leo showed respect towards Aporia and was constantly worried when he got hurt. When Aporia died, Leo was shown to be sadder than anyone else, then he angrily yelled at Z-one for killing him. Before Aporia Dueled Z-one he told Leo that he saw the hope that he possessed within him, and that hope was the very same that Aporia had been seeking.

Knownable Relatives

 * Unnamed Mother
 * Unnamed Father
 * Luna (Younger Twin Sister)
 * Yusei Fudo (Surrogate Older Brother)
 * Akiza Izinski (Surrogate Older Sister)
 * Jack Atlas (Surrogate Father)

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 in names are due to Japanese speakers pronouncing "L" and "R" as the same sound. When he Dueled Haley in the Japanese version, his name was spelled Rua. When the twins Dueled Lester 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 birthday is, and his bloodtype is.

Voice Actresses

 * Japanese : Ai Horanai
 * English : Cassandra Lee Morris (Ep. 12 – Ep. 64), Eileen Stevens  (Ep. 65 – Present)

all information on Leo came from http://yugioh.wikia.com/wiki/Leo