{{Infobox/Yu-Gi-Oh!/Episodeepisode | series = Yu-Gi-Oh! | season image = 5 | image name = Yugioh198.jpg | image size = | image caption = | english en_name = Sinister Secrets - Part 3 | kanji ja_name = KCグランプリ終結 | romaji romaji_name = Kei Shī Guran Puri Shūketsu | japanese translated ja_trans_name = KC Grand Prix Ends | episode series = Yu-Gi-Oh!| number = 198 | japanese air date season = 5| ja_air_date = March 31, 2004 | english air date en_air_date = October 8, 2005 | japanese opening ja_opening = [[OVERLAP]] | japanese ending ja_ending = [[EYE'S]] | english opening en_theme = [[Yu-Gi-Oh! theme]]Theme | english ending screenwriter = [[Yu-Gi-Oh! theme]]Akemi Omode

"'''"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)|''Yu-Gi-Oh!'' second series anime.]] It first aired in Japan on March 31, 2004, and in the US on October 8, 2005.

{{Episode summary|The [[Duel]] between [[Leon von Schroeder]] and [[Yami Yugi]] continues. Zigfried is amused at YamiYugi's claim that he will destroy "[[Golden Castle of Stromberg (anime)|Golden Castle of Stromberg]]". Meanwhile, [[Seto Kaiba|Kaiba]] has his own battle to fight: stopping the virus that has spread through his system.}}

As the final [[Duel]] of the [[KC Grand Championship]] continues, [[Zigfried von Schroeder|Zigfried]] reveals one of the [[card effect|effects]] of "[[Golden Castle of Stromberg (anime)|Golden Castle of Stromberg]]": it forces both parties to battle, and when the opponent's monster is [[destroy]]ed, the opponent shall suffer [[Battle Damagebattle damage]] equal to half that monster's [[ATK]] points.

Another effect of "Golden Castle of Stromberg" is soon revealed: the [[maintenance cost]] of this [[Field Spell Card]] forces the the card's controller to [[send]] half of their [[Main Deck|Deck]] to the [[Graveyard]]. However, Ziegfried Zigfried has edited it so that the opponent had to pay the cost instead of the controller.

Yami Yugi barely survives an attack which would've cost him the Duel, and [[Special Summon]]s an [[Effect Monster]] with an [[Card effect|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, YamiYugi, 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.

YamiYugi'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 comment 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.

Yami Yugi draws (Yugi's Deck: [[#Yami Yugi's Deck depletion|29 → → 28]]). The fourth [[effect]] of "[[Golden Castle of Stromberg (anime)|Golden Castle of Stromberg]]" forces activates, forcing "[[Yami YugiDark Magician Girl (anime)|Yami's]] "[[Dark Magician Girl]]" to attack. "Dark Magician Girl" attacks [[Leon von Schroeder|Leon's]] "[[Pumpkin Carriage (anime)|Pumpkin Carriage]]", but the fifth effect of "Golden Castle of Stromberg" then [[activate]]s, [[destroy]]ing "Dark Magician Girl" and inflicting [[effect damage|damage]] to Yami Yugi equal to half his monster's [[ATK]] (Yami 2200 → 1700). The Since "Dark Magician Girl" was destroyed, the last effect of "[[Glass Slippers (anime)|Glass Slippers]]" then activates, [[equip]]ping itself to "[[Cinderella (anime)|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.

Leon draws. During his On Leon's [[Standby Phase]], the first effect Maintenance Cost of "Golden Castle of Stromberg" requires him to [[send]] half the cards in his [[Main Deck|Deck]] to the [[Graveyard]]. However, the last effect of "Golden Castle of Stromberg" transfers the cost to Yami Yugi (YamiYugi's Deck: 28 → 14). ''(To see a run-through of how Yami's Deck reaches this point, click [[Yu-Gi-Oh! - Episode 198#A Run-through of YamiYugi's Deck Depletiondepletion|here28 → 14]]).)'' Leon uses the effect of "Golden Castle of Stromberg" to Special Summon "[[Forest Wolf]]" from his hand (1800/300) in [[Attack Position]].<ref group=Notes>This is an error, as the written Japanese lore of "[[Golden Castle of Stromberg (anime)|Golden Castle of Stromberg]]" states its controller can only Special Summon a random Level 4 or below monster from the [[Main Deck|Deck]].</ref>  The third effect of "Golden Castle of Stromberg" then forces "Cinderella" to [[attack]]. "Cinderella" attacks Yami directly (Yami 1700 → 400). The third effect of "Golden Castle of Stromberg" then forces "Forest Wolf" to attack. "Forest Wolf" attacks Yami directly, but Yami Yugi activates his face-down "[[Dark Magic Retribution]]", allowing him to [[Special Summon]] "[[Dark Magician Girl]]" (2000/1700) from the Graveyard in Attack Position. "Dark Magician Girl" then intercepts the attack, and [[destroy]]ing s "Forest Wolf" (Leon 2100 → 1900). During the On Leon's [[End Phase]], the last effect of "Dark Magic Retribution" destroys "Dark Magician Girl".

Yami Yugi draws (Yugi's Deck: [[#Yami Yugi's Deck depletion|14 &rarr; → 13]]). Since it has been three turns since "[[Spinning Wheel Spindle]]" was activated, "[[Queen's Knight (anime)|Queen's Knight]]" is Special Summoned to from YamiYugi's Graveyard to his side of the [[field]] in Attack Position (1500/1600)in Attack Position. Yami Yugi Sets 2 two cards. He then activates "[[Card of Sanctity (anime)|Card of Sanctity]]", forcing to force both players to [[Draw a card|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: [[#YamiYugi's Deck: depletion|13 → 7]]). YamiYugi's hand at this point contains "King's Knight", "[[Multiply (anime)|Multiply]]", "Emergency Provisions", "Royal Straight", "Chain Destruction", and "Time Travel".  Yami Yugi Normal Summons "[[King's Knight (anime)|King's Knight]]" (1600/1400) in Attack Position. Since Yami controls Yugi Summoned "QueenKing's Knight" when while he summoned had "KingQueen's Knight"on his side of the field, the effect of "King's Knight" activates, Special Summoning "[[Jack's Knight (anime)|Jack's Knight]]" (1900/1000) from YamiYugi's [[Main Deck|Deck]] in Attack Position (YamiYugi's Deck: [[#Yami Yugi's Deck depletion|7 → 6]]).  Yami Yugi then activates "[[Royal Straight (anime)|Royal Straight]]", to [[Tribute|Tributing]] "Queen's Knight", "King's Knight" and "Jack's Knight" to and [[Special Summon]] "[[Royal Straight Slasher (anime)|Royal Straight Slasher]]" from his Graveyard (2400/1350) in [[Attack Position]]. Yami Yugi then activates the effect of "Royal Straight Slasher", sending to send "[[Kuriboh (anime)|Kuriboh]]" (Level 1), "[[Old Vindictive Magician (anime)|Old Vindictive Magician]]" (Level 2), "[[Giant Soldier of Stone (anime)|Giant Soldier of Stone]]" (Level 3), "[[Big Shield Gardna (anime)|Big Shield Gardna]]" (Level 4) and "[[Curse of Dragon (anime)|Curse of Dragon]]" (Level 5) from his Deck to the Graveyard to and destroy all cards Leon [[control]]s (YamiYugi's Deck: [[#Yami Yugi's Deck depletion|6 → 1]]). "[[Iron Hans (anime)|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 [[banish|removingremove]] his "Royal Straight Slasher" from play until Leon's next Standby Phase.

Leon draws. During his On Leon's Standby Phase, the first effect 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 YamiYugi. Since However, Yami Yugi reveals he cannot pay the [[cost]] with 1 only one card left in his Deck, so "Golden Castle of Stromberg" is destroyed. At the same time, "Royal Straight Slasher" returns to YamiYugi's side of the field (2400/1350) in Attack Position via the effect of "Time Travel"(2400/1350).  Leon, at this point, tries to surrender, but Yami Yugi convinces him not to. Leon activates "[[Monster Reborn (anime)|Monster Reborn]]", Special Summoning "Cinderella" from his Graveyard (300/600) in Attack Position. Since "Cinderella" was Summoned, its effect activates, Special Summoning 1 "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 (anime)|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 in by battle, its effect activates, increasing its ATK by 400 ("Hexe Trude": 2600 → 3000/2100).

Yami Yugi draws "Monster Reborn" (Yugi's Deck: [[#Yami Yugi's Deck depletion|1 → 0]]). His hand now contains "Monster Reborn", "Emergency Provisions" "Multiply", and "[[Chain Destruction (anime)|Chain Destruction]]". He Yami Yugi then Sets a card. He then activates "[[Emergency Provisions (anime)|Emergency Provisions]]", sending to send his Set card ("[[Chain Destruction]]") to the Graveyard to and gain 1000 [[Life Points]] (Yami 200 → 1200). Yami Yugi then activates "Monster Reborn", to Special Summoning Summon "[[Dark Magician (anime)|Dark Magician]]" (2500/2100) from his [[Graveyard]] in Attack Position. He  Yami Yugi then activates his face-down "[[Necromancy]]", to Special Summoning 4 [[random]] monsters from Leon's Graveyard to Leon's side of the field in Defense Position. He summons Summon "[[Little Red Riding Hood]]" (800/1200), "[[Forest Hunter]]"(1200/800), "[[Iron Hans (anime)|Iron Hans]]"(1200/800) and "[[Iron Knight (anime)|Iron Knight]]" (1700→ 700/700) to from Leon's Graveyard to his side of the field in Defense Position. If any of these summoned Summoned monsters are destroyed, all of Leon's monsters will lose 600 ATK for each one destroyed until the End Phase. Because "Iron Hans" is face-up, "Iron Knight" loses 1000 ATK ("Iron Knight" 1700 → 700/700). Yami then activates "[[Diffusion Wave-Motion]]", paying 1000 Life Points (Yami 1200 → 200) to 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]]". The effect of "Necromancy" then decreases the ATK of "Hexe Trude" by 600 for each monster destroyed that was Special Summoned by its effect. With all four destroyed, "Hexe Trude" loses 2400 ATK ("Hexe Trude": 3000 → 600/2100). "Dark Magician" attacks and destroys "Hexe Trude" (Leon 1900 → 0). Yami wins.

Yami Yugi then activates his face-down "[[Diffusion Wave-Motion (anime)|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). ==A Run-through of YamiYugi's Deck Depletiondepletion==

* Turn 11: "[[Golden Castle of Stromberg (anime)|Golden Castle of Stromberg]]" [[mill]]s half his [[Main Deck|Deck]] (14 cards) to the [[Graveyard]] (Deck: 14)* Turn 12: Conducts his normal draw, activates "[[Card of Sanctity]]" (drawing 6 cards), [[Special Summon]]s "[[Jack's Knight]]" from his Deck with the effect of "[[King's Knight]]", and sends 5 [[Monster Card]]s from his Deck to the [[Graveyard]] by the effect of "[[Royal Straight Slasher (anime)|Royal Straight Slasher]]" (Deck: 1)* (By turn Turn 13, : "Golden Castle of Stromberg's" cost cannot send "half" of be paid with only 1 card to in the GraveyardDeck, so it destroys itself.)

* When Yugi activates the effect of "[[Royal Straight Slasher (anime)|Royal Straight Slasher]]", the shot of him drawing six cards from the effect of "[[Card of Sanctity]]" is reused (with the cards on his duel disk changed appropriately) when he was . At that point, Yugi's Deck contains only supposed 6 cards. While drawing his entire deck to draw choose the 5 monsters is appropriate, cardsare still shown in the Deck slot of the duel disk. In addition, by viewing his entire deck, Yugi would have known for certain that the last remaining card in his deck is [[Monster Reborn]] (and consequently that he has a game-winning combo ready). However, he looks surprised when he draws it on the following turn.

* During the scene when “King’s Knight”"King’s Knight", “Queen’s Knight” "Queen’s Knight" and “Jack’s Knight” "Jack’s Knight" put their swords together, all three monsters’ ATK are shown; the ATK of “King’s Knight” "King’s Knight" is incorrectly shown as 1900 when it is really 1600. This was corrected in the dub.

*The dress of "[[Hexe Trude (anime)|Hexe Trude]]'s dress " was made less revealing in the dub. *Cut from the dub is a bit of two kids dueling in a park, using duel disks. One kid orders his "Ruiz" ("[[Beaver Warrior (anime)|Beaver Warrior]]") to attack, but the hologram starts to flutter with static. The other kid's "Gremlin" ("[[Feral Imp (anime)|Feral Imp]]") does the same, and the kid says something's wrong. *Cut also is a shot of [[RebeccaHawkins]] saying that [[Yugi]]'s deck will be halved every round. * In posterior Video and online releases, the international version follow this episode with the 12 episodes of [[Yu-Gi-Oh! Capsule Monsters]],before returning with the next arc,Millenium World. 

* [[Cinderella (anime)|Cinderella]]

* ''[[Hexe Trude (anime)|Hexe Trude]]''* [[Iron Hans (anime)|Iron Hans]]* [[Iron Knight (anime)|Iron Knight]]

* [[Pumpkin Carriage (anime)|Pumpkin Carriage]]

* [[Glass Slippers (anime)|Glass Slippers]]* [[Golden Castle of Stromberg (anime)|Golden Castle of Stromberg]]* [[Monster Reborn (anime)|Monster Reborn]]

* [[Curse of Dragon (anime)|Curse of Dragon]]<ref group=Notes name=straight>This card was [[send|sent]] from Yugi's Deck to the [[Graveyard]] to [[activate]] the effect of "[[Royal Straight Slasher (anime)|Royal Straight Slasher]]".</ref>* [[Dark Magician (anime)|Dark Magician]]* [[Giant Soldier of Stone (anime)|Giant Soldier of Stone]]<ref group=Notes name=straight/>* [[Jack's Knight (anime)|Jack's Knight]]* [[Queen's Knight (anime)|Queen's Knight]]

* [[Big Shield Gardna (anime)|Big Shield Gardna]]<ref group=Notes name=straight/>* [[Dark Magician Girl (anime)|Dark Magician Girl]]* [[King's Knight (anime)|King's Knight]]* [[Kuriboh (anime)|Kuriboh]]<ref group=Notes name=straight/>* ''[[Old Vindictive Magician (anime)|Old Vindictive Magician]]''<ref group=Notes name=straight/>* ''[[Royal Straight Slasher (anime)|Royal Straight Slasher]]''

* [[Card of Sanctity (anime)|Card of Sanctity]]* [[Diffusion Wave-Motion (anime)|Diffusion Wave-Motion]]* [[Emergency Provisions (anime)|Emergency Provisions]]* [[Multiply (anime)|Multiply]]<ref group=Notes name=hand>This card was seen in Yugi's [[hand]].</ref>

* ''[[Royal Straight (anime)|Royal Straight]]''

* [[Chain Destruction (anime)|Chain Destruction]]<ref group=Notes name=hand/>

* [[Cinderella (anime)|Cinderella]]* [[Dark Magician Girl (anime)|Dark Magician Girl]]* [[Pumpkin Carriage (anime)|Pumpkin Carriage]]

* [[Glass Slippers (anime)|Glass Slippers]]* [[Golden Castle of Stromberg (anime)|Golden Castle of Stromberg]]

* [[Beaver Warrior (anime)|Beaver Warrior]]* [[Feral Imp (anime)|Feral Imp]]