Yu - Gi - Oh ! - Episode 198 " Sinister Secrets - Part 3 " , known as " KC Grand Prix Ends " in the Japanese version , is the one - hundred and ninety - eighth episode of the " Yu - Gi - Oh ! " second series anime . It first aired in Japan on March 31 , 2004 , and in the US on October 8 , 2005 . Summary . As the final Duel of the KC Grand Championship continues , Zigfried reveals one of the effects of " Golden Castle of Stromberg " : it forces both parties to battle , and when the opponent ' s monster is destroy ed , the opponent shall suffer Battle Damage equal to half that monster ' s ATK points . Meanwhile , Kaiba and Mokuba reach the control center and begin working on halting the virus program . Mokuba vows that he won ' t let Ziegfried get away with betraying his brother ' s trust . Another effect of " Golden Castle of Stromberg " is soon revealed : the maintenance cost of this Field Spell Card forces the card ' s controller to send half of their Deck to the Graveyard . However , Zigfried has edited it so that the opponent had to pay the cost instead of the controller . Elsewhere around the world , Duel Disk systems begin to malfunction as a result of the virus . Yami Yugi barely survives an attack which would ' ve cost him the Duel , and Special Summon s an Effect Monster with an effect of destroying all of the opponent ' s cards . Unfortunately , it too fails , since Zigfried foresaw that possibility . However , Yami was aiming for something else : he ' s used all but " 1 " card in his Deck . Since the cost rounds down , he can only discard 0 cards , which is not actually considered paying the Field Spell Card ' s maintenance cost . " Golden Castle of Stromberg " is destroyed . The virus is finally halted , and Kaiba realizes Yami Yugi found the weakness of the card . He orders for all systems to be linked to the backup ones and reboot it . Despite getting rid of the Field Spell Card , Zigfried points out that almost all of the gaming data in KaibaCorp has been deleted thanks to the virus . He also points out that Yami Yugi has only one card left in his Deck and when he becomes unable to draw a card from his Deck , Leon wins by default . Leon does not want to defeat Yami Yugi due to what his brother did , so he tries to surrender the Duel , but Yami convinces they should continue the Duel now that the " Golden Castle " is gone . Even though Leon manages to Tribute Summon a very powerful monster , Yami Yugi , by Special Summon ing " Dark Magician " and using a combo of " Necromancy " and " Diffusion Wave - Motion " , is able to win the duel . Yami Yugi consoles Leon : he fought his best and didn ' t give up until the very end . He tells him that he ' s a " true Duelist " . Leon breaks down into tears . Zigfried , being the sore loser he is , claims that the virus program has already managed what he sought . Kaiba comes in and claims that he ' s already restored the main computer to normal . Leon tries to reason with him : he tells him that he knew the whole thing was pointless . Zigfried collapses and mutters that , in the end , he can ' t win over Kaiba . Kaiba claims not just him , nobody can . Leon tries to explain what he ' s learned : if you give up , all ' s over . But if he keeps on moving forward with high spirits , someday , he can accomplish something . He wants to help him , and pleads of him to share his pains with him . Yami Yugi and Yugi are glad that things are finally resolved . Yami Yugi ' s victory is announced worldwide as Weevil Underwood and Rex Raptor curse in Tokyo ( as they wanted to be the ones to defeat Yami ) , and Mai Valentine looks on from another location . Mokuba arranges for Yugi and co . to return to Japan with a KC plane . When Duke comments that he ' d like to meet Serenity , both Joey and Tristan hold him in place and tell him off . The Professor tells Solomon " not to do anything reckless " . Solomon plays strong , but his waist ache comes back . Rebecca tells Yugi that they must have a new Duel in the future . Featured Duel : Yami Yugi vs . Leon von Schroeder . " Duel continues from previous episode . " Yami Yugi has 2200 Life Points remaining and controls " Dark Magician Girl " ( 1000 / 1700 ) in Attack Position . Leon has 2100 Life Points remaining and controls " Iron Hans " ( 1200 / 800 ) and " Cinderella " in Attack Position , " Pumpkin Carriage " ( 0 / 800 ) in Defense Position , and " Glass Slippers " ( equipped to " Dark Magician Girl " ) and " Golden Castle of Stromberg " . Turn 10 : Yami Yugi Yami Yugi draws ( Yugi ' s Deck : 29 → 28 ) . The fourth effect of " Golden Castle of Stromberg " activates , forcing " Dark Magician Girl " to attack . " Dark Magician Girl " attacks Leon ' s " Pumpkin Carriage " , but the fifth effect of " Golden Castle of Stromberg " then activate s , destroy ing " Dark Magician Girl " and inflicting damage to Yami Yugi equal to half his monster ' s ATK ( Yami 2200 → 1700 ) . Since " Dark Magician Girl " was destroyed , the last effect of " Glass Slippers " activates , equip ping itself to " Cinderella " . The third effect of " Cinderella " activates when it is equipped with " Glass Slippers " from another monster , increasing her ATK by 1000 ( " Cinderella " : 300 → 1300 / 600 ) . Yami Yugi Set s a card . Turn 11 : Leon von Schroeder Leon draws . On Leon ' s Standby Phase , the Maintenance Cost of " Golden Castle of Stromberg " requires him to send half the cards in his Deck to the Graveyard . However , the last effect of " Golden Castle of Stromberg " transfers the cost to Yami Yugi ( Yami Yugi ' s Deck : 28 → 14 ) . " ( To see a run - through of how Yami ' s Deck reaches this point , click here . ) " Leon uses the effect of " Golden Castle of Stromberg " to Special Summon " Forest Wolf " from his hand ( 1800 / 300 ) in Attack Position . The third effect of " Golden Castle of Stromberg " then forces " Cinderella " to attack . " Cinderella " attacks directly ( Yami 1700 → 400 ) . The third effect of " Golden Castle of Stromberg " then forces " Forest Wolf " to attack . " Forest Wolf " attacks directly , but Yami Yugi activates his face - down " Dark Magic Retribution " to Special Summon " Dark Magician Girl " ( 2000 / 1700 ) from the Graveyard in Attack Position . " Dark Magician Girl " then intercepts the attack and destroy s " Forest Wolf " ( Leon 2100 → 1900 ) . On Leon ' s End Phase , the last effect of " Dark Magic Retribution " destroys " Dark Magician Girl " . Turn 12 : Yami Yugi Yami Yugi draws ( Yugi ' s Deck : 14 → ; 13 ) . Since it has been three turns since " Spinning Wheel Spindle " was activated , " Queen ' s Knight " is Special Summoned from Yami Yugi ' s Graveyard to his side of the field ( 1500 / 1600 ) in Attack Position . Yami Yugi Sets two cards . He then activates " Card of Sanctity " to force both players to draw until they both have 6 cards in their hand s , letting Yami Yugi draw six cards while Leon draws two cards ( Yugi ' s Deck : 13 → 7 ) . Yami Yugi ' s hand at this point contains " King ' s Knight " , " Multiply " , " Emergency Provisions " , " Royal Straight " , " Chain Destruction " , and " Time Travel " . Yami Yugi Normal Summons " King ' s Knight " ( 1600 / 1400 ) in Attack Position . Since Yami Yugi summoned " King ' s Knight " while he had " Queen ' s Knight " on his side of the field , the effect of " King ' s Knight " activates , Special Summoning " Jack ' s Knight " ( 1900 / 1000 ) from Yami Yugi ' s Deck in Attack Position ( Yami Yugi ' s Deck : 7 → 6 ) . Yami Yugi then activates " Royal Straight " to Tribute " Queen ' s Knight " , " King ' s Knight " and " Jack ' s Knight " and Special Summon " Royal Straight Slasher " from his Graveyard ( 2400 / 1350 ) in Attack Position . Yami Yugi then activates the effect of " Royal Straight Slasher " to send " Kuriboh " ( Level 1 ) , " Old Vindictive Magician " ( Level 2 ) , " Giant Soldier of Stone " ( Level 3 ) , " Big Shield Gardna " ( Level 4 ) and " Curse of Dragon " ( Level 5 ) from his Deck to the Graveyard and destroy all cards Leon control s ( Yami Yugi ' s Deck : 6 → 1 ) . " Iron Hans " , " Cinderella " , " Pumpkin Carriage " , and " Glass Slippers " are destroyed , but " Golden Castle of Stromberg " remains on the field because it cannot be destroyed by other card effects . Yami Yugi then activates " Time Travel " to remove his " Royal Straight Slasher " from play until Leon ' s next Standby Phase . Turn 13 : Leon von Schroeder Leon draws . On Leon ' s Standby Phase , the Maintenance Cost of " Golden Castle of Stromberg " requires him to send half the cards in his Deck to the Graveyard . However , the last effect of " Golden Castle of Stromberg " transfers the cost to Yami Yugi . However , Yami Yugi reveals he cannot pay the cost with only one card left in his Deck , so " Golden Castle of Stromberg " is destroyed . At the same time , " Royal Straight Slasher " returns from the Removed from Play Zone to Yami Yugi ' s side of the field ( 2400 / 1350 ) in Attack Position via the effect of " Time Travel " . Leon , at this point , tries to surrender , but Yami Yugi convinces him not to . Leon activates " Monster Reborn " , Special Summoning " Cinderella " from his Graveyard ( 300 / 600 ) in Attack Position . Since " Cinderella " was Summoned , its effect activates , Special Summoning " Pumpkin Carriage " from Leon ' s Graveyard ( 0 / 300 ) in Defense Position . Leon then Tributes " Cinderella " and " Pumpkin Carriage " in order to Tribute Summon " Hexe Trude " ( 2600 / 2100 ) in Attack Position . " Hexe Trude " attacks and destroys " Royal Straight Slasher " ( Yami Yugi 400 → 200 ) . Since " Hexe Trude " destroyed a monster by battle , its effect activates , increasing its ATK by 400 ( " Hexe Trude " : 2600 → 3000 / 2100 ) . Turn 14 : Yami Yugi Yami Yugi draws " Monster Reborn " ( Yugi ' s Deck : 1 → 0 ) . His hand now contains " Monster Reborn " , " Emergency Provisions " " Multiply " , and " Chain Destruction " . Yami Yugi then Sets a card . He then activates " Emergency Provisions " to send his Set card ( " Chain Destruction " ) to the Graveyard and gain 1000 Life Points ( Yami 200 → 1200 ) . Yami Yugi then activates " Monster Reborn " to Special Summon " Dark Magician " ( 2500 / 2100 ) from his Graveyard in Attack Position . Yami Yugi then activates his face - down " Necromancy " to Special Summon " Little Red Riding Hood " ( 800 / 1200 ) , " Forest Hunter " ( 1200 / 800 ) , " Iron Hans " ( 1200 / 800 ) and " Iron Knight " ( 1700 → 700 / 700 ) from Leon ' s Graveyard to his side of the field in Defense Position . If any of these summoned monsters are destroyed , all of Leon ' s monsters will lose 600 ATK for each one destroyed until the End Phase . Yami Yugi then activates his face - down " Diffusion Wave - Motion " to pay 1000 Life Points ( Yami 1200 → 200 ) and allow his " Dark Magician " to attack all of Leon ' s monsters once each . " Dark Magician " attacks and destroys Leon ' s " Little Red Riding Hood " , " Forest Hunter " , " Iron Hans " and " Iron Knight " ( " Hexe Trude " : 3000 → 600 / 2100 ) . " Dark Magician " then attacks and destroys " Hexe Trude " ( Leon 1900 → 0 ) . Featured cards . The following cards appeared in this episode . Cards in italics debuted here .