Reginald Kastle

Ryoga Kamishiro, nicknamed Shark, is a character in Yu-Gi-Oh! ZEXAL and is one of Yuma Tsukumo's friends and rivals. He was originally a cold and malicious person but has grown quite humble.

Design
Ryoga has dark blue eyes, pale skin and dark purple hair, similar to tentacles hanging down, befitting his Deck theme of aquatic creatures as his hair is similar in appearance to an octopus. His other accessories include a spiked pendant similar to the one Yuma Tsukumo wears, as well as another pendant hanging down by a chain. He also owns a red, spiked D-Gazer. His attire includes a dark blue jacket over a black shirt and dark pants. When in his school attire, he wears a white shirt with green-lined sleeves and a collar. During his National Circuit days, Ryoga wore a white top with a purple waist coat and his usual dark pants.

Personality
Ryoga flaunts his power about by taking the Decks of the people he beats, making them squirm in the process such as when he defeated Tetsuo. When he became possessed by the Numbers, he became quite violent, destroying the scenery surrounding him during the Duel. After being disqualified from the National championships for trying to look at the other competitors' decks, he became bitter and uncaring, the way he held himself at the beginning of the series. He does have some honor though; he returned Tetsuo's deck as agreed upon losing to Yuma, as well as keeping all the decks he'd stolen from people completely intact.

His defeat to Yuma seems to have humbled him in a way; he isn't as overly cruel to people, as shown by returning Yuma's pendant after he won an Ante Duel with it at stake. He also seems to put more faith in bonds and friendship, shown by his willingness to form a team with Yuma during the Tag Duel with Rikuo and Kaio, even entrusting him with a card that would allow them to win the duel.

National Circuit Days
In the past, Ryoga was a well known, and favorite duelist within the National Duel Circuit. This stardom got to Ryoga's head which caused him to look at his opponent's deck when they dropped it within a waiting room in order to please his fans and to have an advantage which caused Ryoga to be disqualified from the National Duel Circuit and have a life long ban placed over his head to prevent him from dueling there again. After this ban, Shark turned into a delinquent and began to steal the decks of his opponents once he beat them where he obtained the nickname Shark due to the fact that he uses an ocean-themed deck and because he rips the decks of the opponents out of their hands swiftly and maliciously.

Even though this has happened, Yuma defended Ryoga who believes that everyone has done something in their past which they regret, as Yuma used "Numbers" even when he promised he wouldn't, because he was afraid he would lose.

Present Day
Shark first appeared whilst Yuma and Kotori were observing the Duels going on within their middle school grounds. He was seen quickly defeating Tetsuo without taking one point of damage, after this he then took Tetsuo's Deck and belittled him along with his friends. When Yuma stood up for Tetsuo, Shark asked Yuma what was most precious to him, to which Yuma looked down at his pendant. Seeing this as a chance, Ryoga snapped Yuma's pendant and broke it whilst his friends restrained Yuma from hitting Ryoga. Shark then suggested that Yuma should Duel him in order to retrieve Tetsuo's Deck back, to which Yuma accepts.

Shark is then seen within the city square, and then begins his Duel with Yuma. Within the Duel, Ryoga quickly gains an advantage with his "Big Jaws" and "Aqua Jet" combo. He then traps Yuma with his traps and then his passion for winning Duels gets the better of him and allows him to be possessed by Numbers to which he then proceeds to Xyz Summon "Number 17: Leviathan Dragon".

As the Duel progresses, Ryoga begins to toy with Yuma taking his Life Points down to a small fraction. But Yuma managed to come out of this, and managed to defeat Shark with his "Number 39: Utopia" at 5000 ATK, which knocks Ryoga out, winning Yuma the match.

Shark then awoke, and gave Yuma Tetsuo's Deck, and said that Yuma is different than everyone that he has faced before. He then walks off silently.

He is then later seen riding on a motorcycle, after Yuma's Duel with Fuya Okudaira. It's a rouge motorcycle with a single thick wheel.



Whilst Yuma was late to school, he ran across a crossing to almost be hit by Shark whilst he was on his motorcycle. After Yuma is belittled by his friends who believe that his victories over Shark and Tokunosuke Omoteura were just because of his Numbers he decides to find Shark and challenge him to a rematch, without using the help of Astral or his Numbers.

When Yuma finds Shark, he refuses to Duel as his previous loss to Yuma caused him to give up Dueling. Yuma then proceeds to chase Shark and annoy him by requesting a Duel until he accepts (based on his reactions during the duel it can be assumed that he only accepted in order to defeat the Numbers.). As the Duel progresses, Shark's burn strategy begins to take its toll on Yuma. Shark tells him use his "Numbers" anyway, so Yuma brings out "Utopia". It was not enough, as Shark weakened it with "Killer Frilled Shark", then proceeded to negate its effects and destroy it with his "Black Ray Lancer". With a final direct attack from "Submersible Carrier Aero Shark", Yuma lost the Duel, losing his pride along the way. Yuma bet his pendant in the Duel as a prize, but when Shark took it, he threw it behind him onto the ground beside Yuma, saying that it wasn't worth destroying as well as warning him not to bother him again.

Shark soon overheard Rikuo and Kaio's plot of raiding the Heartland museum in hope of trying to steal a valuable deck. He also discovered that both thugs were possessing two Number cards. When Kaio and Rikuo found Shark listening on their plan, he is forced to go along with them. Before going, he tells their younger brother, Ginji, to run so he dosent become involved in the dangerous raid.

Upon arriving at the museum, he found Yuma standing in their way, not allowing them to pass without beating him in an Duel first. He was shocked when Yuma bet his "Number 39: Utopia" on the duel. Shark warned Yuma not to be concerned for him, but Yuma said he won't leave him alone to rob the deck. Yuma also pointed out that Rikuo and Kaio were using him, and that their hideout is not a place for him to stay plus both Yuma and Shark are comrades. Shark then decides to duel with Yuma against Rikuo and Kaio in a 2-on-2 Tag Duel. On his first move, he Xyz Summoned "Sumbersible Carrier Aero Shark" and managed to deal effect damage to Rikuo. But after Rikuo Xyz Summoned "Number 61: Volcasaurus," he activated "Volcasaurus's" effect, which destroyed "Submersible Carrier Aero Shark" and dealt Shark damage equal to "Submersible Carrier Aero Shark's" ATK.

Having all their moves countered and with the appearance of "Number 19: Freezerdon", which gave "Volcasaurus" its Overlay Units back, Shark and Yuma were pushed into a corner. After summoning "Utopia" and having it prevented from attacking by Kaio's trap "Avalanche", Yuma used its effect to protect Shark from attacks which would have caused him to lose. After having "Utopia" and the newly summoned "Black Ray Lancer" are destroyed by "Volcasaurus" (avoiding losing by "Damage Diet"), Shark narrowly avoids losing from a direct attack by using the trap "Last Entrust", ending the battle phase and giving Yuma a card needed to win. After eliminating Kaio by forcing him to use his "Compensation Exchange" trap, which saved Volcasaurus by taking damage equal to its ATK, Yuma used "Monster Reborn" to bring back Shark's "Black Ray Lancer" and equip it with Shark's "Armored Xyz" he entrusted to him earlier. It allowed him to give "Lancer" the properties of "Utopia", letting it destroy "Volcasaurus" and attack directly for the win.

Afterwards, Shark comments that his card was able to improve Yuma's game, allowing him to keep it before smiling and walking off.

When Kotori was trying to ask people about the Number cards, she ran into Shark, who told her that she should not get involved with those cards and that they are things that neither of them should understand in detail.

Decks
Ryoga's Deck consists of monstrous looking sea creatures such as sharks and krakens. He utilizes a Burn and Beatdown strategy in order to quickly gain the advantage through cards such as "Submersible Carrier Aero Shark" and "Explosive Urchin", with a focus on using Level 3 monsters to Xyz Summon Rank 3 Xyz Monsters.