Seto Kaiba ( Duel Links ) Seto Kaiba is a playable Legendary Duelist in " Yu - Gi - Oh ! Duel Links " . This is a video game depiction of Seto Kaiba , a character from the " Yu - Gi - Oh ! " anime . White Gate Key s are required to Duel Seto Kaiba at the Gate . Biography . When " Yu - Gi - Oh ! Duel Links " is started after it is successfully downloaded in its entirety , Kaiba will appear confronting Yami Yugi , declaring that when he ( Kaiba ) defeats him , Yugi will have to call him the King of Games . He then wonders aloud if Yugi even has the cards to confront him . Depending on the player ' s choice , either he or Yami Yugi can then be utilized in the subsequent tutorial Duel . After the player concludes their initial in - game tutorial , Kaiba makes an appearance , broadcasting a global announcement across the world of Duel Links . He declares that the Duelists must have realized where they ' ve arrived by now , before revealing that the Duelists present are all here in order to test their skills in the next evolution of Dueling . He proudly states that this world is the perfect place to determine who the real champion is , before rhetorically asking who will wear the crown as Duel World King . Kaiba then reveals that Duel World is divided into different Stages , and he prompts Duelists to reach the final stage to " claim the throne , " defeating all who stand in the way of their dreams . Concluding his announcement , he invites Duelists to come to Duel World for their greatest challenge , to test themselves to their breaking points , and dares them individually to become the Duel World King . He then disappears in laughter . At this point , if the player had chosen Kaiba for their tutorial Duel , he will immediately reappear in Duel World ; otherwise , he will only make his next appearance after the player reaches Stage 15 . In either case after his appearance , he will declare that everything is proceeding as planned , since the Duelists he invited will help complete Duel World with every Duel they engage in . He then reminisces of Yugi , declaring that both he and Yugi will have their final Duel in this world . ( Kaiba ' s dialogue ends at this point , unless the player had chosen Kaiba as their initial character , in which case Kaiba additionally declares that Yugi will fall against his trusted ally : " Blue - Eyes White Dragon " . ) Yami Yugi route . If the player chooses Yami Yugi as their initial character in " Yu - Gi - Oh ! Duel Links " , they will also encounter the following instances of unique dialogue , as they attempt to unlock Seto Kaiba as a playable character . Decks . Set Sail for the Kingdom . Level 20 . Skill : " Peak Performance " ( Seto Kaiba starts the Duel with " Mountain " on his field . ) Level 40 . Skill : " Blue - Eyes Advent " ( Seto Kaiba starts the Duel with " Blue - Eyes White Dragon " on his field . ) Level - up rewards . The following lists are the rewards the player accumulates from having Seto Kaiba reach a certain Level . Duel rewards . When dueling against Level 40 Seto Kaiba , these are the only cards that can drop ; at lower levels , cards from the standard pool for Legendary Duelist s may also drop . Mokuba Kaiba