Yu - Gi - Oh ! - Episode 137 Summary . Kaiba and Joey continue with their Duel , while Tristan and Duke give Joey their support ; they start wondering why both Yugi and Téa aren ' t back yet . Meanwhile on top of the Duel Tower while Téa is still passed out from Marik ' s mind control , Ishizu tells Yami Yugi that her brother is growing weak and he will until he is no more and tells him that he can destroy the evil within Marik ' s dark side by defeating him in his next Duel but if Yugi loses it would be the end of everything . Just then Téa finally regains consciousness and awakes , Yugi immediately notice and rushes over to her Téa had no idea why she was up at the tower , with the last thing she remembers was watching Joey ' s Duel with Kaiba . During the Duel , Kaiba eventually managed to defeat Joey . Kaiba , having nothing that matters to him anymore decides to leave the island and detonate it , though Ishizu tries to convince him to watch the final Duel as well as help Yugi beat Yami Marik . Kaiba refuses to do anything as the only point of his tournament was so that could be the # 1 Duelist again , but because of his loss against Yugi , that ' s no longer possible , so his only option now is destroying the island . Mokuba , after remembering what Yugi and Joey said about his brother in their Duels against him , states to Seto that destroying the island won ' t do any good for anyone , including themselves . Due to this and remembering on how his brother was in the past compared to now , Mokuba reveals that he really wants to see his brother as he used to be . Instead of causing more damage , Kaiba should try and help Yugi beat Yami Marik since Kaiba did figure out a way to beat " The Winged Dragon of Ra " and was planning on using it against Yami Marik before he lost . Kaiba is left conflicted , but he ultimately decides to do so . As the final Duel begins , Kaiba gives Yami Yugi the card he planned to use to defeat Yami Marik . Featured Duel : Seto Kaiba vs . Joey Wheeler - Part 3 . " Duel continues from previous episode . " Joey has 100 Life Points remaining and controls " Hayabusa Knight " ( 1000 / 700 ) in Defense Position and one set card . Kaiba has 700 Life Points remaining and controls " Blue - Eyes White Dragon " ( 3000 / 2500 ) in Attack Position . Turn 12 : Joey Wheeler Joey draws " Baby Dragon " and subsequently Normal Summons it ( 1200 / 700 ) in Defense Position . Turn 13 : Seto Kaiba Kaiba draws " Stop Defense " and subsequently activates it to switch Joey ' s " Hayabusa Knight " ( 1000 / 700 ) into Attack Position . " Blue - Eyes White Dragon " attacks " Hayabusa Knight " , but Joey activates his face - down " Nutrient Z " to increase his Life Points by 4000 before Battle Damage is calculated ( Joey 100 → 4100 ) . " Blue - Eyes White Dragon " then destroys " Hayabusa Knight " ( Joey 4100 → 2100 ) . Kaiba Sets a card . Turn 14 : Joey Wheeler Joey draws " Time Wizard " and subsequently Normal Summons it ( 500 / 400 ) in Attack Position . He then activates " Time Wizard ' s " effect . Joey succeeds in the effect , so he can transform " Baby Dragon " into " Thousand Dragon " ( 2400 / 2000 ) . Before " Time Wizard ' s " effect can affect " Blue - Eyes White Dragon " , Seto activates his face - down " Interdimensional Matter Transporter " to remove " Blue - Eyes White Dragon " from play for one turn . At the End Phase , " Blue - Eyes White Dragon " returns to the field ( 3000 / 2500 ) in Attack Position due to the effect of " Interdimensional Matter Transporter " . Turn 15 : Seto Kaiba Kaiba draws " Thunder Dragon " . He then activates the effect of " Thunder Dragon " to discard it and add two more " Thunder Dragons " from his Deck to his Hand . Kaiba then activates " Polymerization " to fuse his two " Thunder Dragons " together and Fusion Summon " Twin - Headed Thunder Dragon " ( 2800 / 2100 ) in Attack Position . Kaiba then activate s " Quick Attack " to allow " Twin - Headed Thunder Dragon " to attack the turn it is summoned . " Twin - Headed Thunder Dragon " attacks & destroys " Thousand Dragon " ( Joey 2100 → 1700 ) . " Blue - Eyes White Dragon " attacks directly ( Joey 1700 → 0 ) . Featured cards . The following cards appeared in this episode . Cards in italics debuted here .