History StoryBreakerPower / YuGiOh

* Kiryu's Dragon ace from the Dark Signers arc; Hundred Eyes Dragon. Summoning it is straightforward (the usual Dark Synchro summon), and it has the same stats as Blue-Eyes White Dragon. However, it's real strength are its two broken effects. Hundred Eyes Dragon lets him gain the effects of ''[[AllYourPowersCombined every]]'' DARK monster in the graveyard. With Kiryu's main handless combo strategy resulting in most of his cards being in the graveyard, this makes Hundred Eyes Dragon ridiculously hard to get rid of. And even if it gets destroyed, it lets Kiryu choose to ''any'' card from his deck to his hand; no restrictions on what he can get. Understandably, it was severely nerfed for the IRL card game, only getting to copy one effect at a time and searching an Earthbound Immortal on destruction.

* Don Thousand takes this trope up to eleven, even by series standards. His Deck makes use of a Field Spell that lets him activate Spells and Traps from his Deck at will, some of which include ''changing what Spell or Monster that an opponent has activated or Summoned''. It also lets his own Xyz Monsters use their effect without needing Xyz Materials, blatantly ignoring the limiting factor inherent in the Xyz Monster design, and with minimal resources, employ a combo that can OneHitKill his opponents. When that's beaten, he switches up to Summoning a monster with ''10,000 ATK'' along with other effects that let him steal the protagonists' monsters for his use. When that is defeated, he gets to Summon a monster with '''[[SerialEscalation 100,000 ATK]]''' that resists destruction and forces the opponent into a MortonsFork of attacking into its ridiculous ATK score or getting an instant loss. It takes the protagonists' own Story Breaker Power to defeat him.

** In the real - life card game, Exodia is inconsistent at best. But with Yugi (or other protagonists') [[MagicPokerEquation canon ability to draw any cards they want at any time]], it would make any duel completely unfair.

* [[Manga/YuGiOh The manga]] zig-zags the trope with the Exodia cards, which singlehandedly gave Yugi his second victory against Kaiba's much more powerful deck. Not long afterward, they were pitched into the sea by a rival using a cheap ploy. It's anyone's guess how much the ability to make an instant win would have helped out Yugi in the following arcs. As time went on, however, Exodia was shown to be the very definition of AwesomeButImpractical, riddled with weaknesses and drawbacks, the least of which being the issue of drawing all five cards out of a deck of at least forty without Yugi's insane luck of the draw on your side. Unless someone had a deck specifically revolving around Exodia, using the thing was extremely difficult, and even then there were inherent problems, as shown when Yugi fought the first Rare Hunter. The individual pieces could be dead draws when a duelist needed a strong monster, and they were vulnerable to attacks on the hand. One Card Destruction could spell ruin for the mighty Forbidden One. Ultimately, Exodia stopped showing up in its vanilla form, and duelists instead went for different incarnations of it: Gozaburo Kaiba's Exodia Necross, or Adrian Gecko's Exodius, the Ultimate Forbidden Lord.

* The Virtual World arc introduces a Deck Master mechanic, in which each player picks a monster that can be Summoned to the field at any time, but with the drawback that its controller loses if it is destroyed. The Deck Master also gains a unique ability that can be used at various points in the Duel. Some of the Deck Master abilities are ludicrously overpowered, such as Judge Man, who can destroy all monsters the opponent controls even during their turn. This is offset by the arc villains, the Big 5, mostly being too incompetent at the game to use them to their fullest ability. For instance, Nezbitt's Deck Master, Robotic Knight, has the ability to deal 500 damage for every Machine type monster discarded (up to 3 per turn). As previously mentioned, such burn damage is overpowered in a 4000 LP format (just ask ''[[VideoGame/YuGiOhDuelLinks Duel Links]]'' players who played against similar decks), but he uses it in the most inefficient manner. In a 3 on 1 duel, the best use would be to target a specific player for 1500 damage to take them out one-by-one, but every time he uses it, he instead inflicts 500 damage to all players, thus diluting the amount of damage done.

* The Super Fusion/Super Polymerization, a focal point of the third season and gained permanently in the fourth. This little number could fuse together any two monsters, even if the opponent was controlling them, essentially letting the user make their own cards (at the very least, nearly every time it was used, it created a card that made no sense for the owner to have). Every time it was used, it immediately shifted the balance of the duel -- and that was just in the game; the card could also fuse together just about anything, including living beings and entire universes. It was only used to fuse something besides cards once, and its user, Judai, spent most of the final season either playing friendly duels that didn't warrant ungodly power or conveniently not drawing it.

* Kiryu's Dragon ace from the Dark Signers arc; Hundred Eyes Dragon. Summoning it is straightforward (the usual Dark Synchro summon), and it has the same stats as Blue-Eyes White Dragon. However, it's real strength are its two broken effects. Hundred Eyes Dragon lets him gain the effects of ''[[AllYourPowersCombined every]]'' DARK monster in the graveyard. With Kiryu's main handless combo strategy resulting in most of his cards being in the graveyard, this makes Hundred Eyes Dragon ridiculously hard to get rid of. And even if it gets destroyed, it lets Kiryu choose to ''any'' card from his deck to his hand; no restrictions on what he can get. Understandably, it was severely nerfed for the irl card game.

* The Shining Draw ability possessed by the protagonist Yuma Tsukumo when fused with Astral, which allows him to create any ZEXAL Weapon he wants... and later, any card he wants. Every ZEXAL Weapon conveniently possesses [[NewPowersAsThePlotDemands exactly the correct abilities to win the current duel,]] and they can be alarmingly complex--presumably, the only reason Yuma doesn't just declare that the cards he creates with Shining Draw automatically win the Duel is out of fairness. Add in the fact that Yuma's deck is very OTK-friendly, and Yuma spends much of the second series either out of commission or unable to fuse with Astral just so that every single episode didn't become "summon Hope, Shining Draw, win."

* The main protagonist Yusaku Fujiki/Playmaker's main ace monster is this, and a GameBreaker in the real game that was eventually Forbidden and later received an erratum. Firewall Dragon can return monsters on either field or in the Graveyard to the hand up to the number of monsters co-linked with it, or Special Summon any monster from the player's hand if a monster it points to goes to the Graveyard. The first ability would have been able to wipe almost ''any'' monster off the field with no strings attached, while the second could have enabled Playmaker to swarm the field almost endlessly far sooner than he eventually did. He subsequently only used Firewall Dragon ''five times'' before it was Forbidden in the real game and it stopped appearing in the anime, and when he did use it KryptoniteIsEverywhere tended to be in effect, as four times out of three his field was either too depleted to use it properly or his opponent had an effect to counter it (most notably, main rival Revolver/Varis's Borreload Dragon couldn't be targeted by monster effects). The one time none of that was in play, Playmaker brought Firewall Dragon out against a {{Mook}} and curbstomped him in a single turn.

* On the heroes' side, Aoi's Trickstar deck is incredibly powerful. It's a very consistent burn deck that can do heavy damage, in a show where life points start at a mere 4000. The deck was also infamously during its heyday, resulting in many of its cards being hit. In theory, a deck like this would annihilate pretty much everything that comes it's way. But for this series, nearly every character packs dozens of monsters that can negate effect damage, often as an arbitrary secondary effect just because.

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* ''Anime/YuGiOhGX'' has Super Fusion/Super Polymerization, a focal point of the third season and gained permanently in the fourth. This little number could fuse together any two monsters, even if the opponent was controlling them, essentially letting the user make their own cards (at the very least, nearly every time it was used, it created a card that made no sense for the owner to have). Every time it was used, it immediately shifted the balance of the duel -- and that was just in the game; the card could also fuse together just about anything, including living beings and entire universes. It was only used to fuse something besides cards once, and its user, Judai, spent most of the final season either playing friendly duels that didn't warrant ungodly power or conveniently not drawing it.
* ''Anime/YuGiOh5Ds'' had Kiryu's Dragon ace from the Dark Signers arc; Hundred Eyes Dragon. Summoning it is straightforward (the usual Dark Synchro summon), and it has the same stats as Blue-Eyes White Dragon. However, it's real strength are its two broken effects. Hundred Eyes Dragon lets him gain the effects of ''[[AllYourPowersCombined every]]'' DARK monster in the graveyard. With Kiryu's main handless combo strategy resulting in most of his cards being in the graveyard, this makes Hundred Eyes Dragon ridiculously hard to get rid of. And even if it gets destroyed, it lets Kiryu choose to ''any'' card from his deck to his hand; no restrictions on what he can get. Understandably, it was severely nerfed for the irl card game.
* ''Anime/YuGiOhZEXAL'' has the Shining Draw ability possessed by the protagonist Yuma Tsukumo when fused with Astral, which allows him to create any ZEXAL Weapon he wants... and later, any card he wants. Every ZEXAL Weapon conveniently possesses [[NewPowersAsThePlotDemands exactly the correct abilities to win the current duel,]] and they can be alarmingly complex--presumably, the only reason Yuma doesn't just declare that the cards he creates with Shining Draw automatically win the Duel is out of fairness. Add in the fact that Yuma's deck is very OTK-friendly, and Yuma spends much of the second series either out of commission or unable to fuse with Astral just so that every single episode didn't become "summon Hope, Shining Draw, win."
* Also from ''ZEXAL'' is Number 7: Lucky Straight. Anyone who possessed this card was given WindsOfDestinyChange powers, as demonstrated by the original owner Charlie [=McCoy=]. Charlie was able to roll 6's on his dice roll effects whenever he needed to, and gave him a come from behind victory against a duelist that would make Judai and Atem jealous. Against Yuma, Charlie was able to gain ''100,000'' life points thanks to Lucky Straight's powers and a continuous spell card requiring dice rolls. Yuma could only win after breaking the BargainWithHeaven that granted Charlie Lucky Straight's powers, which only happened because Charlie played a very convenient spell card that allowed the prophecy to be fulfilled. Even though Charlie could no longer use the power, anyone he transferred ownership of the card to still could, though this doesn't seem apply to Yuma and Astral, possibly due to the Key preventing the luck effect like it does a Number's possession.

* Don Thousand in ''ZEXAL'' takes this trope up to eleven, even by series standards. His Deck makes use of a Field Spell that lets him activate Spells and Traps from his Deck at will, some of which include ''changing what Spell or Monster that an opponent has activated or Summoned''. It also lets his own Xyz Monsters use their effect without needing Xyz Materials, blatantly ignoring the limiting factor inherent in the Xyz Monster design, and with minimal resources, employ a combo that can OneHitKill his opponents. When that's beaten, he switches up to Summoning a monster with ''10,000 ATK'' along with other effects that let him steal the protagonists' monsters for his use. When that is defeated, he gets to Summon a monster with '''[[SerialEscalation 100,000 ATK]]''' that resists destruction and forces the opponent into a MortonsFork of attacking into its ridiculous ATK score or getting an instant loss. It takes the protagonists' own Story Breaker Power to defeat him.
* [[spoiler:Z-ARC]] from ''Anime/YuGiOhArcV'' runs a deck designed to be a MasterOfAll with the four Summon methods, focused on summoning his ace monster and uses cards with various interlocking defensive effects that make it [[NighInvulnerability very difficult to get rid of]]. His main Pendulum cards also have never-before-seen scales of 0 and 13 to allow him to Pendulum Summon anything. On top of that, it also is capable of summoning upgraded, corrupted versions of all 4 Dimensional Dragons consistently ''on the opponent's turns'', and even has the ability to destroy cards added to the hand outside the Draw Phase, rendering Action Cards and tutoring moot. Even if by some miracle you manage to destroy it, it's a Pendulum Monster, so he can use his aforementioned Pendulum scales to summon it again. Unlike other instances of this trope with regards to past ''Yu-Gi-Oh!'' villains, his PurposelyOverpowered cards serve to illustrate [[spoiler:Z-ARC's]] fear of losing, something that the rest of the cast begin to call him out on. In the end, it takes four cards specifically designed to be his AchillesHeel [[spoiler:and Yuya deliberately sabotaging Z-ARC from the inside for the last blow]] in order to finally take him down.
* Crystal Wing Synchro Dragon, from the same series. Its effect lets it NoSell and destroy a monster on the field once per turn, and take that monster's ATK. When it battles a Level 5 or higher monster (essentially, anyone's strongest cards), it gains their ATK, on top of its own. This means that it can destroy nearly any monster ''and'' inflict 3000 points of damage. Naturally, Yugo only duels four times with it: two end with instant victory, the third has him defeated by Rin, due to the recursion effects of her corrupted Fusion monsters Windwitch - Crystal Ball, and the fourth has him lose to [[EvilCounterpart Yuri]], whose Greedy Venom Fusion Dragon just so happens to have a Graveyard effect to destroy Crystal Wing.
* In ''Anime/YuGiOhVRAINS'' main protagonist Yusaku Fujiki/Playmaker's main ace monster is this, and a GameBreaker in the real game that was eventually Forbidden and later received an erratum. Firewall Dragon can return monsters on either field or in the Graveyard to the hand up to the number of monsters co-linked with it, or Special Summon any monster from the player's hand if a monster it points to goes to the Graveyard. The first ability would have been able to wipe almost ''any'' monster off the field with no strings attached, while the second could have enabled Playmaker to swarm the field almost endlessly far sooner than he eventually did. He subsequently only used Firewall Dragon ''five times'' before it was Forbidden in the real game and it stopped appearing in the anime, and when he did use it KryptoniteIsEverywhere tended to be in effect, as four times out of three his field was either too depleted to use it properly or his opponent had an effect to counter it (most notably, main rival Revolver/Varis's Borreload Dragon couldn't be targeted by monster effects). The one time none of that was in play, Playmaker brought Firewall Dragon out against a {{Mook}} and curbstomped him in a single turn.
** Yusaku's final ace monster, Accesscode Talker, is absurdly good and is also a GameBreaker in the real game that's regularly used to close out games. First, it's base attack is the usual 2300 that all of Yusaku's "Code Talkers" have, but it gains 1000 ATK for every Rank a Link Monster used in its Link Summon has. In the real game, this pretty much means that it comes out swinging with at least 4000 ATK right off the bat (when it was used in the anime, it got a whooping 7300 ATK due to using the Link-5 Firewall Dragon Darkfluid in its summon). It's second effect, which is why it's so effective at closing out games, is that it can destroy any card on the field by banishing a Link Monster from the field or graveyard, it can repeat this effect by banishing a Link Monster with a different attribute from those that have already been banished for its effect, and ''it cannot be responded to'', which means that it can pretty much destroy an entire board with little to no resistance once it comes out. Yusaku only gets to pull him out in [[EleventhHourSuperpower the last episode]] to counter the usual overpowered monster the FinalBoss has.
* ''Anime/YuGiOhVRAINS'' also has roughly one per FinalBoss of the season.

** Bohman in the second season didn't necessarily have an overpowered monster, but an overpowered Skill. He was already capable of surpassing main protagonist Playmaker by not only using Storm Access to grab a random Link Monster from the Data Storm, but doing so in a Master Duel where it wasn't even part of the rules, but in his final duel with Playmaker he upgrades this to Master Storm Access, which can not only be used once per turn, but once per ''opponent's'' turn as well, and created the first known Link-5 monsters in the series. Playmaker winds up needing outside interference to shut this Skill down a few times just to survive.
** On the heroes' side, Aoi's Trickstar deck is incredibly powerful. It's a very consistent burn deck that can do heavy damage, in a show where life points start at a mere 4000. The deck was also infamously during its heyday, resulting in many of its cards being hit. In theory, a deck like this would annihilate pretty much everything that comes its way. But for this series, nearly every character packs dozens of monsters that can negate effect damage, often as an arbitrary secondary effect just because.
* In ''Anime/YuGiOhSEVENS'', ''duelists'' rather than cards come across as this, though their cards do play a big factor.
** Nail Saionji and his Maximum Monster Yggdrago the Sky Emperor. It can't be destroyed by Traps, can destroy any Level 8 or lower monster once per turn, and change a defensive monster into Attack Position and has 4000 ATK to boot. Note that Rush Duel as a whole is roughly early DM levels of power. And since it's a Maximum, Nail can drop it basically whenever he wants since his Deck focuses on drawing through his cards and rearranging them until he gets the three pieces of Yggdrago. He beat main protagonist Yuga in their first Duel and it took Yuga's own Maximum to barely scrape out a win as Nail shuffled his Maximum into his Deck ''twice''. Following this Neiru is generally on the heroes' side, but his account is banned due to the conditions of his and Yuga's Duel so he can't just wreck any opponent they come across. When he finally ''did'' Duel again, he joined Yuga and Roa in the Team Battle Royal and basically swept the competition with Yggdrago until they hit the finals. Gakuto came close to defeating Yggdrago, but was eventually forced to tie with a ''very'' lucky draw. In the second season, when he does Duel again it's on the villains' side.

** Asana Mutsuba's Wyrm Excavator the Heavy Cavalry Draco. Like Yggdrago, it can't be destroyed by Traps, but it also gains ATK for every card in the player's hand, in a format where players automatically draw until they hold five cards each turn, and has an effect to draw more cards ''and'' destroy any Traps the opponent was hoping to use. Asana curbstomped Yuga when they first dueled, and he was only able to force a draw with his own Maximum because Asana hadn't got the chance to replenish her hand. While the above-mentioned Yggdrago still remained, Wyrm Excavator was destroyed so Asana couldn't curbstomp any opponent she dueled in one move and wasn't restored until the end of the series by Galian, who used it against Asana but was defeated before he could replenish his hand.

* [[spoiler:Zarc]] from ''Anime/YuGiOhArcV'' runs a deck designed to be a MasterOfAll with the four Summon methods, focused on summoning his ace monster and uses cards with various interlocking defensive effects that make it [[NighInvulnerability very difficult to get rid of]]. His main Pendulum cards also have never-before-seen scales of 0 and 13 to allow him to Pendulum Summon anything. On top of that, it also is capable of summoning upgraded, corrupted versions of all 4 Dimensional Dragons consistently ''on the opponent's turns'', and even has the ability to destroy cards added to the hand outside the Draw Phase, rendering Action Cards and tutoring moot. Even if by some miracle you manage to destroy it, it's a Pendulum Monster, so he can use his aforementioned Pendulum scales to summon it again. Unlike other instances of this trope with regards to past ''Yu-Gi-Oh!'' villains, his PurposelyOverpowered cards serve to illustrate [[spoiler:Zarc's]] fear of losing, something that the rest of the cast begin to call him out on. In the end, it takes four cards specifically designed to be his AchillesHeel [[spoiler:and Yuya deliberately sabotaging Zarc from the inside for the last blow]] in order to finally take him down.