TV-Series
Description
Dragon Ryu is a central character introduced in the Duel Masters Victory season, serving initially as the primary rival to the protagonist Katta Kirifuda before evolving into a close friend and powerful ally. His true origin is not that of an ordinary human duelist but a powerful creature from another world. In his original form, he is known as Ryusei Kaiser, the Eternal, a guardian who fought alongside the alien princess Prin Prin to stop the invasion of a malevolent force known as Gallows Hellish Dragon, Brink of Despair. When their plan failed, Ryu saved Prin Prin by sending her to the human world, and he followed with his two subordinates, Sakon and Ukon, transforming into human forms to continue his search for her.

While in the human world, Ryu participates in numerous dueling tournaments, quickly earning a reputation as the strongest duelist in the region. His personality is marked by a calm confidence and a dramatic flair, often appearing arrogant toward rivals like Katta. However, this exterior masks a deeply honorable and caring nature. This is demonstrated early on when, after defeating Katta in a duel where Katta had wagered his precious Raging Dragon Lord card, Ryu refuses to take it, recognizing its significance. His primary motivation throughout the Victory season is finding and protecting Prin Prin, the princess he was sworn to guard, and retrieving the special card that contains her essence.

Ryu's role in the story begins as a mysterious and formidable rival who tests Katta's abilities. He quickly becomes a catalyst for Katta's growth, pushing him to unlock his latent dueling potential, which Ryu himself hypothesizes involves a unique ability to commune with the spirits of the cards. Their relationship is competitive but built on mutual respect. When Ryu is defeated and seriously injured by the villainous Onsen, who is also hunting for Prin Prin's card, he makes the crucial decision to trust Katta. Ryu willingly reverts to his true card form, Forever Kaiser, the Meteor, and asks his former rival to use him as a card in the final battle against Onsen. This act transforms their relationship from rivalry to a deep, symbiotic partnership. From that point on, Ryu remains with Katta, often staying in the necklace that once held Katta's own treasured card. His bond with Prin Prin is equally central; his devotion to her is absolute, and his actions are consistently driven by a need to ensure her safety, even as she proves to be a spirited and independent presence in his life.

Throughout subsequent series like Duel Masters Victory V and V3, Ryu's development continues. He remains a steadfast ally and guardian, often providing Katta with crucial information about the creature world and its conflicts, such as the appearance of the Outrages and Oracles. He faces his own challenges, including being controlled by an enemy and suffering a serious defeat that forces him to tap into darker Outrage forms like Ryusei, Ex Revolver to fight back. His journey ultimately leads to a poignant conclusion where Prin Prin uses her powers to take away his card form, causing him to lose his creature self, a sacrifice that highlights his growth from a warrior to a being capable of deep emotional bonds and difficult choices. Later, it is noted that he chose to live as a human, sealing off Katta's powers to protect the balance between the human and creature worlds.

As a duelist, Ryu is exceptionally skilled and his deck reflects his multifaceted nature. Early on, he primarily uses a deck combining the Water and Darkness civilizations, with his signature avatar creature being Ryusei Kaiser, the Eternal. As the series progresses, he incorporates cards from the Fire and Light civilizations as well. His most notable abilities are tied to his true nature as a creature. He can transform between his human guise and his powerful creature forms, such as Ryusei Kaiser, the Victorious, and can also combine his essence with his subordinates, Sakon and Ukon, through a process called Psychic Link. This allows him to become even more formidable entities like Gaial Ryusei Dragon, Star Dragon King, and ultimately Gaial Ore Dragon, the Vainglory, demonstrating his ability to fight on an immense scale.