Hoist by His Own Petard/Anime and Manga


 * Near the end of the Stone Ocean arc of JoJo's Bizarre Adventure, Enrico Pucci achieves godlike status as he has gained the ability to speed up time and move the universe towards destruction and recreation. Pucci has already killed off most of the heroes, and all that's left is Tagalong Kid Emporio Alnino. Pucci stops the universal reset just short of a full cycle in order to catch Emporio at the one moment they were both in the same location -- the Green Dolphin Street prison -- in order to kill him. Pucci thinks this will be easy enough, seeing as how Emporio has one of the weakest abilities in the entire series, but unknownst to him, Emporio borrowed one of his fallen friend's abilities, and just as Pucci is in the perfect position to kill Emporio, Emporio is in the perfect position to kill Pucci. The kid surprises him with a weather-changing ability and uses it to poison him with fatal levels of oxygen.
 * Digimon Savers: The Big Bad Kurata committed genocide,created collateral damage to to take over the world in the mean time he sucked in void bending devices,so what does he do when he gets defeated? He activates a huge explosion that causes the Digital World to crash into Earth,and he disappears into a light while doing it.This action also is the final straw for the Final Boss.
 * Mazinger Z: Big Bad Dr. Hell designed a Mechanical Beast (Spartan K5) resembled a Gladiator... but it was a pacifist refused attacking unless provoked. Baron Ashura requested testing it against Mazinger Z anyway, but Kouji actually befriended it. Enraged, Ashura ordered several Iron Masks putting a time bomb on Spartan K5 to blowing it up. Later, the Mechanical Beast was accidentally goaded into attacking Mazinger Z and UTTERLY BEAT THE CRAP OUT OF IT. Right when it was about of delivering the final blow, the bomb went off. Kouji and his friends got sad. Hell and Ashura got angry.
 * In episode 27, Ashura captures Aphrodite A and scans it in order to learn how building a photong engine. He hands over the records to an Iron Mask and commands him go and hand them out to Dr. Hell. Though, a Kikaiju -that had been deployed by Ashura to delay Mazinger Z- is returning to base right on that moment, and steps on the Iron Mask, killing him and destroying the information they had obtained.
 * UFO Robo Grendizer: The Vegans managed to make huge technological breakthroughs by exploiting ores of the material radioactive known as Vegatron. However, it led to his planet becoming unstable, forcing them to find new worlds to colonize. The vegatron bombs they rained upon Fleed scorched the Fleedian army to ashes, but they also turned the planet they intended to colonize on a radioactive wasteland. And finally, Vegatron radiation destroyed their homeworld and rendered their Moon Space Base -their last safe haven- inhabitable.
 * Soukou no Strain kills off Medlock by having Ralph override her ship and order her own killer robots to tear her apart. The real Irony is that she had recently turned good, and the good guys assumed she got out safely like they did and didn't think anything of looking for her...
 * Many Sailor Moon characters died this way (in fact, the protagonists themselves rarely kill anyone, except for monsters-of-the-week) -- at least when they were not offed by the Big Bad for their constant failures, betrayed by their peers, or redeemed. Kunzite died of his own reflected attack (though Sailor Moon still qualifies for that kill by reflecting it); Mimete died when she used a machine built by Eudial, whom she killed; Tellu was eaten by the giant plant she summoned; Viluy had her Nanomachines turn against her and "erase" her; Cyprine and Ptilol (regarded as one person) were tricked into blasting each other, and Sailor Lead Crow was sucked into the black hole that she tried to use against Sailor Moon, though only because her black hole device was sabotaged by her sociopathic teammate, Tin Nyanko.
 * This only happened in the anime; the Scouts regularly killed villains in the manga.
 * Yu-Gi-Oh,
 * In the first season, when Yugi defeated Ryuji Otogi (Duke Devlin) at Dungeon Dice Monsters, it was, in a way, Otogi's fault; he had inadvertently designed the DDM version of Dark Magician, Yugi's favorite monster, incredibly powerful, with abilities that made Yugi able to use it with almost as much synergy as he did in Duel Monsters. Yugi could not help but thank him for making such an accurate version of his favorite card before he delivered the winning blow.
 * In the second season of when Yugi dueled Marik's mind-slave Strings, the only way he was able to beat his invincible card setup was to use it to his own advantage so that his monster would be destroyed and regenerated an infinite number of times within a single turn, and due to one of the effects Marik had on the field, Strings was forced to keep drawing cards from his deck every time the monster regenerated, until he ran out of cards and lost the duel by default.
 * In the Virtual World arc, the Quirky Miniboss Squad all suffer a defeat this way. Oshita (Gansley) insults Yugi's Kuriboh, and loses because of its effects; Otaki (Crump) laughs at Black Magician Girl (Dark Magician Girl) for being useless without her master, so Anzu (Téa) Summons it; Oka (Johnson), a smug lawyer, falls for an obvious bluff; Ota (Nesbitt), who viewed Shizuka (Serenity) as the weak link, loses to her St. Joan; Daimon (Leichter), who viewed himself as superior to Kaiba, loses when Kaiba Summons a card strong enough to attack his Kill Sat; and when merged together, they view Jounouchi (Joey) as The Load to Yugi, only to have Jounouchi's cards be instrumental to victory.
 * When Yami Bakura duels Yami Marik, he loses because of this. In the anime, he tries to win this way by using Dark Designator in order to add Ra to Yami Marik's hand, and then Exchange in order to steal Ra. However, the moment he tries to summon Ra, Marik activated a trap card that drained Bakura's sacrifices of their attack power, meaning Ra had zero attack points. He then sacrificed it to summon a new monster, which allowed Marik to revive Ra with Monster Reborn, the card Marik took from Bakura because of Exchange. The manga plays it out a bit differently, but is still ultimately this trope. After using Dark Designator to add Ra to Marik's hand, Bakura activates Multiple Destruction, a hand destruction card, sending Ra to the graveyard, which gives Marik the chance to revive it with Monster Reborn. In both versions, Bakura was unaware of Ra's additional powers.
 * In the Waking the Dragons arc, the Seal of Orichalcos was an utterly overpowered card, but once it was activated, whoever lost the Duel lost their soul. There were only two instances onscreen where the person who activated the card didn't lose the Duel, and one of those was a draw.
 * Yu-Gi-Oh GX:
 * In season one, the second of the Shadow Riders, Camula, had a card called Illusion Gate. It destroyed all monsters her opponent controlled and then let her summon one monster from her opponent's Graveyard. The cost? If she lost the Duel, her soul would be forfeit to the  Sacred Beasts. She normally used her Shadow Charm to offer someone else's soul instead, but when Judai (Jaden)'s own charm cancelled out hers, she was left with no choice but to stake her own soul. And naturally, she lost.
 * In season two, Judai dueled X, a Pro Duelist who used a Mill Deck; Judai won by decking him out. X was a very unpleasant person (even Edo (Aster), who witnessed the duel, didn't like him), so this was sort of poetic justice. Of course, Judai does this using one of his Neo-Spacians, and a common theme with his duels is that the villains never understand how they work and never take them into consideration. Even the most Crazy Prepared villain can never prepare for something he knows nothing about.
 * Yu-Gi-Oh 5 Ds:
 * The first example was way back in episode two. Yusei duels a guy who uses Insect cards, and had a Spell Card on the field (Ant Lion's Vengeance/Retribution of the Ant Lion) that damages a player whenever their monster goes to the Graveyard. Yusei pulls off a combo that destroys all three of his opponent's monsters, and lets his own Spell card do the rest. (Given that the guy purposely destroys one of his own Insects earlier in the duel to use its effect, he's obviously not entirely clear on how his own card works; long story short, he was an Ineffectual Sympathetic Villain, more or less.)
 * Arguably, this is how Yusei defeated Jack the first time. Jack was in his pre-Heel Face Turn days, and tried to troll Yusei by summoning Red Dragon Archfiend and Stardust Dragon, the latter of which is Yusei's ace card that Jack stole. Unfortunately for him, Yusei was expecting that, activates Harmonium Mirror to seize control of it, and wins. Well, he would if the duel hadn't been interrupted, but Yusei won in Jack's eyes, much to his horror.
 * The duel with Takasu plays it in another angle. While locked in the Facility, Yusei is forced into a duel with the head jailer. The idea of his Iron Chain strategy is to exhaust the opponent's deck, but Yusei reveals that his last two cards (from a deck all cobbled together from other jailed duelists) actually depended on a high graveyard count, and he wins the duel with them.
 * This could also be construed as how Team 5Ds defeated Team Ragnarok. Harold's Trap Card, Gjallarhorn, would have banished all three of his Divine Beast monsters in three turns and then deal damage to Yusei equal to their ATK, and make them and Harold nearly invincible until that happened. Yusei was able to turn this card against him by summoning Shooting Star Dragon for the first time. This causes Harold to use his Odin's Eye Trap, which again, is what Yusei was expecting; he counters with a Trap of his own to shanghai control of the Trap, making the three Divine monsters vulnerable; a second Trap causes their Scores to drop to zero, meaning when the effect of Gjallarhorn finally activates, Yusei takes no damage at all. Harold, however, is now defenseless, and wide open.
 * In Yu Gi Oh Bonds Beyond Time, Paradox's Sin set does him in. Paradox's set essentially hinged on weakening his opponents' monsters enough so that his overpowered beasts could curbstomp Yami Yugi, Judai and Yusei, killing them. Yami Yugi starts the unraveling when he takes back Yusei's stolen Stardust Dragon and it was more or less a defensive waiting game, tanking attacks and rescuing fallen monsters until the time was right to flatten Paradox and save all of time. Not that taking on all three of them at once was what fans would have considered a good idea...
 * Minor example in Yu-Gi-Oh! Zexal.in the episode where Rio demanded a duel from her brother, Shark. Rio tried to win by using a Field Spell that benefits Water-Attribute monsters and Xyz monsters, and used them to gain an advantage for a turn, summoning a powerful Xyz called Ice Princess Zereort. Unfortunately, she seemed to forget that her brother also specialized in Water-Attribute Xyzs, and was able to use the Field Spell to summon a far more powerful one called Shark Caesar, which was able to wipe her out.
 * Yu-Gi-Oh! ARC-V:
 * Shingo steals two of Yuya's cards and gives him the weak monster Block Spider as an insult, saying it's nothing but trash. When they duel, Block Spider deals the final attack to Shingo.
 * Later in the series, Yugo invokes this trope against a trio of Obelisk Force soldiers, wiping out their entire monster lineup, causing their own Spell Card, Ancient Armageddon Gear, to deal damage to them equal to the total ATK of the monsters they just lost.
 * In Mahou Sensei Negima, Negi used the same power Rakan tried to use on him. It failed to keep him down for the count though.
 * Dragon Ball Z
 * A good example of the monster variety: Babidi is done in by Majin Buu (while Buu was his father's creation, not his own, he intentionally released him).
 * Frieza was cut in half by his own attack (he even lampshades it) which led to his first demise (though he got better later on).
 * Once in a movie and once in the series, Garlic Jr. opens a hole to the Dead Zone, an empty dimension, to try to capture our heroes. No points for guessing what happens both times. Even worse, being immortal, the Dead Zone is the ONLY known thing which could potentially defeat him. And he let it be used against himself TWICE. He was asking for it, really.
 * Dr. Gero, thrice (in the "real" timeline and in the two future timelines).
 * Four times if you count GT.
 * And in the original Dragon Ball, Tao Pai Pai got blown up by his own grenade, as Goku kicked it back to him (although like Frieza, he made an Unexplained Recovery later on. In both cases, they came back as cyborgs.)
 * In Rurouni Kenshin the puppetmaster Gein surrounds Aoshi with oil soaked wires that he lights causing a forest fire. Aoshi uses Onmyô Hasshi to hit Gein with a Kodachi, and reveals that he has tied a wire Gein had left during the battle. Gein begs him not to kill him but Aoshi pulls Gein into the fire Gein had set himself killing him. Aoshi escapes the fire by using a hole he had dug earlier.
 * In an early episode of Fullmetal Alchemist, Ed does battle with an alchemist who transmutes a sword and is later impaled by it. Needless to say, he doesn't get better. This also shows up much later in the Brotherhood series when one of the generals awakens the Mannequin Soldiers so they can take back the city. They promptly eat him.
 * The main villains of both series also fall victim to this. In the first anime Dante, tired of Gluttony's whining over the loss of Lust, transmutes his reason away and turns him into a mindless monster. She is later killed by him because he's gone berserk. In the second anime, Pride eating Kimblee proves his downfall when Kimblee's soul ends up distracting him at a crucial moment and causing his death (something Pride never even considered, because he assumed it was impossible for any soul he consumes to maintain its individuality). Father's attempt to absorb Greed for his Philosopher's Stone also backfires when Greed uses the connection between them to use his Homunculus power on Father, turning his body to charcoal and leaving him vulnerable.
 * Naruto:
 * Gato, the gangster who hired Zabuza and Haku, gets slaughtered by Zabuza.
 * Zaku ended up having his arms blown up by his own air tubes (implants which let him perform sonic and air pressure attacks) after Shino snuck some of his bugs up into them, clogging them.
 * Sasori the puppet master gets impaled by his first creations: puppets made to look like his own parents, wielded by his own grandmother. She suggests that the human heart left in him made him hesitate upon seeing them rushing toward him, rather than dodge it.
 * And after he was resurrected, he was defeated again by getting trapped in his previous puppet body, controlled by Kankuro, the same guy who he EASILY defeated before.
 * In Filler news, two of the three Jannin from the Land of Greens arc were whacked by having their own powers used against them. The first was Gentle Fist'd by Hinata in a way that smothers him in his own magnetic powder, effectively making his jutsu into a ball of suck by breaking the "off" switch; and the second had his ice-crystal death ray reflected back at him by Naruto's headband.
 * The third was also defeated because he was crushed by Chouji who swallowed the water from his jutsu.
 * Almost happened to Deidara when Sasuke pinned him to his explosive clay bird with two large shurikens and sent the bird plummeting down to a minefield he had set earlier, but he manages to escape.
 * It almost happened in a flashback as well, when Itachi used genjutsu to trick Deidara into wrapping explosive around himself instead of Itachi, but Itachi stopped him because it was his mission to get Deidara to join Akatsuki.
 * Pain lost one of his remote-controlled bodies when he used it to absorb Naruto's Sage chakra. Without proper training, said chakra turns people into stone frogs.
 * Kisame suffers this twice. First, his own sword Samehada betrays him for Killerbee/the Eight-Tails because he fed it so much of his chakra while they fought. Then it turns out that the huge water jutsu he used to drain the Eight-Tails chakra and trap Killerbee attracted the attention of Raikage and company. Raikage and Killerbee (rejuvenated by the chakra Samehada just gave him) promptly team up to decapitate Kisame. While this was Just As Planned, even he said it worked a little too well.
 * Sasuke absorbed Orochimaru into his body using the technique Orochimaru intended to use to take over Sasuke's body.
 * Danzo's death is also an interesting case. Having spent his whole life preaching his principles that a shinobi should never show any emotions in battle, and consider the mission to be above comrades, guess how he died? Sasuke pierced his Chidori right through his teammate (whom Danzo had held hostage) to kill Danzo.
 * In The Prince of Tennis, Hajime Mizuki attempts to use Yuuta Fuji's desire to defeat his hated-loved older brother Shuusuke, by (among other things) teaching him a Deadly Upgrade-type skill that could seriously injure him - without telling the kid about the last detail. Well, when it's Mizuki's time to play against the older Fuji, the other deliberately gives him the advantage... and then completely trashes him, all because he's pissed off at Mizuki for the way he treated Yuuta.
 * In the Grand Finale of Mai-HiME, after the Obsidian Lord sheds his host body and reveals his true Eldritch Abomination form, he taunts the heroine and says that as long as the HiME Star (supposedly the prime source of the violence that's surrounded their school) hangs in the sky above their school, he will keep regenerating. Cue about a dozen charging, re-energized HiME and one blown-the-heck-up celestial being, leaving him wide open to be blasted into oblivion.
 * Fate Stay Night: It is already ironic that Kirei Kotomine was killed with the Azoth dagger he gave Rin years before. What is even more interesting is that the dagger was given to him in the prequel by Rin's father, Tokiomi Tohsaka who was Kirei's teacher. It was then used to stab Tokiomi by Kirei while Tohsaka's Servant Archer (Fate/Zero 's Archer, aka, Gilgamesh) watched impassively.
 * Magical Girl Lyrical Nanoha:
 * Toredia was an insane Orussia Liberation War activist that experimented on mass-producing the Mariages in StrikerS Sound Stage X, planning to use them to attack the capitols of numerous countries, saying that they needed to know pain. He was devoured by the Mariages before he could execute this plan.
 * Precia Testarossa, desperate to reach Al Hazard before dying of her disease or being arrested by the TSAB, tried to go do the dimensional transference when she had nine out of 21 Jewel Seeds, short of even the 14-seed bare minimum she suspected she would need. She falls to her death as the transference fails and her lair collapses.
 * In One Piece:
 * Even though no one dies, Luffy is beaten around by Foxy for nearly their entire fight. Foxy uses both his power to slow down time and mirrors to reflect his "slow beams." At the end of the fight, however, he's caught by one of his own beams, reflected from a shard of the same mirrors he used earlier, allowing Luffy ample time to set up a truly epic finishing punch.
 * Also with Eneru, the very gold ball he grafted onto Luffy's arm meant to slow him down becomes the very thing that ends up stopping Eneru's energized death ball and defeating the fake "god".
 * Moria uses his 'Shadows Asguard' technique in order to absorb one thousand shadows on the island to fight Luffy. While he's much bigger and stronger, he's also slower and struggling to keep the shadows in. Luffy defeats him handily through a combination of Gear 2nd and Gear 3rd.
 * Sugar forced an unconscious Usopp to eat a grape that he had tried to force her to eat. She thought it was poison (although it actually wasn't a conventional poison). Usopp's startling and horrifying reaction to eating the grape scares her unconscious and gave her a fear of long noses and things that look like long noses. And, of course, the things she did did stopped happening
 * Subverted in Rave Master with Six Guard's Sean. When he's knocked out by his own sleep-inducing power, he ends up fighting in his sleep and is even stronger than when he's awake. He grinds his teeth, too.
 * In Death Note:
 * One of the Death Note owners, Kyosuke Higuchi, is killed when his notebook is repossessed by Light, who recovers his memories and writes Higuchi's name in a scrap that he tore out of the notebook earlier.
 * Light himself suffers this fate at the very end of the anime when Ryuk makes good on his promise to Light in the very first episode and writes Light's name into the Death Note.
 * Subverted in Bleach during the fight between Kurotsuchi and Szayel Aporro. Szayel possesses Kurotsuchi's giant-demon-baby Bankai. Just as it starts to turn on him, it self-destructs, with Kurotsuchi remarking that he'd obviously already thought of that. Apparently someone's been doing their reading.
 * AND used straight. Kurotsuchi's awesome in that particular respect. He works in a job where being eaten is a job hazard. So what does he do? He implants packets of drugs inside himself and his lieutenant so anything that takes a bite out of them or otherwise consumes them gets a nasty overdose.
 * ...how many jobs do you know where being eaten isn't a hazard?
 * Charlotte traps Yumichika in a technique that will slowly kill him while making him completely undetectable to the outside world, giving a Hannibal Lecture on how Yumichika will die alone and unmourned. However, Yumichika reveals that now he can finally use his secret, ultimate technique without fear of Squad 11 finding out, and kills Charlotte.
 * Hachigen kills Barragan by teleporting his rotting arm into Barragan's stomach, causing him to age himself to death.
 * Tosen gets a taste next. When his hollow form gives him the ability to see, he becomes so focused on his new-found sight to the exclusion of everything else, allowing Hisagi, his former lieutenant, to sneak up on him and land the finishing blow from behind.
 * In 421, this happens to Aizen. Relying on the Hogyoku for power was fine when it still considered him a worthy master. The moment it didn't, the Hogyoku took back all of the power it had given him leaving him vulnerable to Urahara's sealing kidou.
 * IN 466, Yukio tries to kill Toshiro with an inescapable Zerg Rush of Eldritch Abominations programmed to zone in on Toshiro's location and crush him. Then Toshiro flashsteps right next to Yukio and freezes his Fullbring. Yukio can't do anything but scream in terror as his own monsters surround him and Toshiro, knowing full well that Toshiro will be able to dodge their attack while he can't.
 * Robotech: The Shadow Chronicles is basically an epitome of this trope. Basically REF has weapons based on technology provided by Haydonites. When they clash, the question becomes: will Haydonites manage to turn humans' Haydonite-based weapons against humans, or will humans defeat Haydonites with Haydonite-based weapons? Both actually happens, but in the end humans win, at least for the moment.
 * In the Bile Fascination-filled Queens Blade, the assassin Melona's primary means of attack is to squirt some sort of acidic fluid... from her breasts. Reina defeats her by blocking off her nipples with her Breast Plate, causing the acidic liquid to back up, swelling Melona's breasts to massive sizes.... and blowing them up.
 * Ranma ½ includes this on a few occasions, usually as a way for Ranma to beat opponents who, for whatever reason, outclass him. The best example is the Musk Dynasty story; Ranma's opponent Herb is far stronger and better trained at ki attacks then Ranma is, and knows how to disrupt the Hiryu Shoten Ha, which normally feeds off of the opponent's ki (which makes it a tentative example of this trope). Realizing that his opponent's attacks have left large quantities of ki floating loosely, he tricks his foe into apparently destabilizing the Hiryu Shoten Ha again- instead, Herb actually gives Ranma what he needs to gather all of the available ki, coalesce it into a single massive bolt, and drop it right on his head.
 * In an earlier story, the Date Monster of Watermelon Island, Ranma is stuck in female form and defenseless against Tatewaki Kuno, who has lost his delusions and thus is capable of actually concentrating on defeating Ranma for once. Aware that his Training from Hell has conditioned him to attack watermelons, s/he slips one onto Kuno's head, whereupon he knocks himself out cold and restores his memory- and thus his delusions.
 * The Martial Arts Dining story might also count by a technicality; Ranma's winning move, the Parley du Foie Gras, not only takes advantage of a loophole in the rules, but also turns Piccolet Chardin's normally advantageous mutations into Ranma's key to victory. Piccolet's rubber-like face allows him to eat faster then Ranma can, but also makes it easy for Ranma to force his own food down Piccolet's throat.
 * Actually referred to by name in an anime-exclusive OAV; early into the Christmas Scramble OAV, Kodachi mockingly points out that Kuno's unidentified but huge present is far too big to even get through the door, never mind into Akane Tendo's stocking. Kuno, horrorstruck, points out that he's been hoisted with his own petard (probably not in the original Japanese, though, as Kuno's Shakespearean references are a Woolseyism). And is promptly squashed under Shampoo's bicycle.
 * In Mobile Suit Gundam Wing Endless Waltz features a Heroic example of this trope. Heero uses his Twin Buster Cannon to destroy the Big Bad bunker. Though Heero survives Wing Gundam Zero is destroyed by the third shot's recoil.
 * Ah, but the super weapon with a programming defect may as well be the same as the mad scientist whose creations kill him in the end. This also happened in the live-action movie, G Savior, directly to the main antagonist.
 * Mobile Suit Gundam SEED Destiny has the Federation once again trying to nuke ZAFT into space dust... only to get spectacularly one-upped when ZAFT's Neutron Stampeder detonates their nukes in-flight and even while still in the launch tubes. And yes, it's every bit as plausible and awesome as it sounds.
 * On a different scale, Blue Cosmos extremists incited the previous war by surprise-nuking Junius 7, killing millions of civilians. The second war begins by ZAFT extremists surprise-deorbiting the remains of J7 and chucking it at Earth because their families died on the installation. You know, just in case one didn't realize that the whole theme of the series is Cycle of Revenge provoking a Lensman Arms Race...
 * In the mid-season of Code Geass R2, when he is badly wounded and expecting help from Charles, V.V. instead gets his Code taken from him by Charles out of anger for lying to him too many times, and is left to die.
 * Jessie Mavia in Kinnikuman lost to Kinnikuman when he was goaded into going on the offensive. This was a mistake because, while Jessie is a master at move counters and reversals, he has no original moves of his own. Taking the initiative as he did left him wide-open to Kinnikuman reversing Jessie's attacks.
 * In Pokémon Diamond and Pearl, Paul released his Chimchar because it lost one too many battles, and considered it weak. In the Sinnoh League, he was defeated by Ash who used the same Chimchar...as a fully evolved Infernape.
 * Kodai, the Big Bad of Pokémon Zoroark Master of Illusions, doesn't die, but his own TV network is used to air his Engineered Public Confession to Crown City and bring about his downfall.
 * Bianca's Minccino in Black and White had a dreadful habit of cleaning anything it found dirty. Bianca pulled out a Poké Ball that was just as unclean as Ash's badge case (she delivered that to him as well), and when Minccino saw that, it darted up to clean it off. After that, though... wiggle, wiggle, wiggle, click.
 * In Digimon Xros Wars, Neptunemon is killed by his own trident. It has a homing ability, and Shoutmon X4 uses that to his advantage and jumps behind Neptunemon, causing the trident to have to pierce through him to reach its target.
 * Baccano! provides an indirect example of this. After first inflicting damage on Szilard Quates herself, Ennis, one of his created homunculi, gives Firo Prochainezo instructions with her dying words on how to finish him off. Consequently, since the method of killing Szilard involves absorbing his knowledge, Firo is able to save Ennis.
 * In Fairy Tail you have Toby who was tricked by Natsu of all people to scratch himself in the head with his electrified claws.
 * Most of The Seven Kin of Purgatory were defeated this way.
 * Tenchi Muyo has a spectacular moment in Episode 7. The episode's main plot of Ryoko and Ayeka trying to win Tenchi's heart reaches its peak when they trick Mihoshi into returning to the Galaxy Police and locking Washu in her lab before turning on each other. Everything falls apart spectacularly when Sasami defeats an alarm Ayeka put in to keep Ryoko out, the two girls finds out Washu was already in his room, fall prey to said alarm (which launches them into the lake) and, for good measure, Mihoshi returns... and crash lands on the house.
 * Gold and Silver from Yaiba are both defeated by their own features: Silver is knocked out when he accidentally shot his electrical laser while in a water pool and Gold is impaled by Yaiba's sword after the latter took advantage of Gold's super strength and super elastic arms to get propelled with enough force and speed towards the titan.
 * In Ichiban Ushiro no Dai Maou, Manipulative Bitch Fujiko tries to trick Akuto into dosing himself with a Love Potion that would make him her devoted slave and allow her to control his powers. That is until Keena steals the potion and bakes it into an extra large helping of rice that is freely offered to the student body to defuse a tense situation. Cut to Fujiko "enjoying" her unwanted all-girl harem.
 * Reiji Mizuchi from Metal Fight Beyblade loves striking fear into his opponents till they're broken wrecks. Ginga ultimately delivers an epic Shut UP, Hannibal on him. The sight of Ginga not being afraid of him causes him to have a Villainous Breakdown and be overwhelmed by his own fear, allowing Ginga to defeat him. He's last seen as the same broken wreck he typically left his opponents in.
 * In Pokémon Special, Black only managed to beat Lenora because she had her Stoutland spam Take Down, a move that, while powerful, whittled down its HP and allowed it to be taken out in one good hit.
 * Lupin III manages to use Inspector Zenigata's own knowledge of the facts against him when Zenigata foolishly lets him know that he was onto him for saying "Gas Chamber" instead of "electric chair". Zenigata manages to lose enough time just running to the execution chamber to call off the execution that Lupin's prison break succeeds once again.
 * In the anime version of THE iDOLM@STER President Kuroi convinces the audio technician from the Idol Jam to conveniently forget where he put the CD with the 765PRO idols songs. This comes to bites him in the rear, when Chihaya starts to sing in acappella, making the tech (and crowd) be so moved by the scene that he restarts the audio in the next chorus, effectively creating a greater effect on the public than it would be if she had just started singing normally.
 * Also, this little stunt was the last drop for his own group of Idols who didn't want to keep up with his crap anymore and quit his company before the song Chihaya was singing even ended.
 * In Kamen Rider Spirits, Riderman has to deal with his old enemy Marshall Armor, whose thick armor deflects all but the strongest attacks. So Riderman manages to drill a single hole in the shell, then pump it full of bullets, which bounce around inside Armor's shell and shred him to pieces.
 * In Ultimate Teacher Ganbachi plants a spike to the ground in order to kill Hinako who was dropping from above, only to be nudged towards the spike and have Hinako drop on top of him, impaling him in the process.