History Main / SealedEvilInADuel

* ''Manga/{{Inuyasha}}'': Five hundred years before the story's main feudal setting, the most powerful {{miko}} and the most powerful {{youkai}} of the era fought. Unable to defeat each other, the {{miko}} performed one last desperate spell that trapped their souls for all eternity, in a manner that ensured their eternal battle had minimal impact on the world. The two original souls are almost spent, which threatens the Shikon no Tama's continued existence, so Naraku offers it the chance for eternal survival: replacement of the original souls with his and Kagome's. Kagome selflessly wishes for the jewel to cease existing, thereby ending the threat and allowing the original souls to find peace.
* The plot of ''Manga/{{Naruto}}'' commences with the Fourth using a variant of a sealing technique which summons a shinigami that devours both him and his opponent, damning them to do battle in its belly for all eternity. However, he used another technique with it that made the target (or maybe just half of it) instead become SealedEvilInACan. The Third Hokage later uses the same technique on Orochimaru, but didn't have the strength to get all of them, instead inflicting a WoundThatWillNotHeal. This begs the question how the battle is going between The Third Hokage and Orochimaru's ''arms''.
** It's also mentioned that it might just be a legend, and it probably just kills you. It's not like any of the previous users or victims of the technique, [[UndeadAuthor being dead/eternally sealed in a demon's innards]], are in any position to tell anyone. However, the phrase "summoning contract" implies terms are spelled out between the summoner and summoned. If the contract stipulates the summoner is going into the summoned's stomach, then it will happen if you want the rest of the contract carried out. We eventually find out from Kabuto that souls being sealed in such a fashion ''do'' have a different fate than those who die normally, [[BarredFromTheAfterlife as it prevents them from ascending to the normal afterlife on a different plane]] (luckily, there are techniques that can allow them to escape) which in turn prevents them from being brought back by Impure World Resurrection.
*** The myth is eventually proved true when Orochimaru uses his body as a physical vessel for the Shinigami and slits his stomach open. This frees his arms and allows the Hokages to be summoned.
* ''Anime/XamdLostMemories'' ends with Nakiami sealing herself in the Quickening Chamber for a thousand years to offset the darkness of the Hiroken Emperor.

* ''Manga/{{Claymore}}'' does it twice: once for Luciela, a former top warrior of the Organization-turned-Abyssal one, who is sealed away by her sister Raphaela (the two of them eventually become the Destroyer); the second time when dying Clare uses her last strength to seal both the Destroyer and Priscilla in a giant flesh cocoon, trapping them in a battle of willpower...for how long? No one is certain yet.
* ''Manga/BusoRenkin'': The final battle between Kazuki and the BigBad results in using the full power of his weapon to launch himself and Victor to the moon where they can fight without harming anyone until a cure for their WalkingWasteland condition can be created.

* In ''Manga/KenichiTheMightiestDisciple'' YAMI (evil) do this to the good guys by luring their strongest (Hayato Fūrinji) into an equal fight. They fight for several days non-stop. It seems the winner will be the one to scrounge/hunt-down more nutritional food in between attacks, blocks and dodges. The stalemate is finally broken when a fox that Hayato considered eating but spared when he saw that it had a family [[AndroclesLion distracts his opponent at a crucial moment]]. They don't appear to need sleep, however.
* Played with to some degree in the second season of ''Anime/DogDays'': Legend tells of how the Hero King Adel had defeated the Demon Lord Valeri and then sealed him along with herself, so that she could make sure Valeri didn't break free. However, it turns out that this "demon king" was the brother of the queen who summoned this Hero King, and he took part in fighting the demons that plagued the land at Adel's side. He took on the name of Demon King as a joke, then occasionally caused trouble to remind the complacent of the threat, and in the end both of them willingly sealed themselves together so that they could help if a new crisis occurred.
* This ''may'' have happened at the end of ''Anime/TurnAGundam''. At the end of their final duel, the Turn A and the Turn X manages to inflict a MutualKill on each other, causing their respective Moonlight Butterfly systems to go berserk and encase both mobile suits into a cocoon-like shell. Considering that they also use the same nanomachines to repair themselves and the Turn X demonstrated at least some degree of [[SapientSteed independent will]] when it came to fighting the [[WorthyOpponent Turn A]], it is possible that the two machines attempted to repair the damage they suffered by mutually trying to consume each other for raw materials, endlessly breaking down the other to repair themselves.
** As for their pilots, Loran managed to get far enough away in time. [[BigBad Ghingham]] wasn't so lucky - and since he's the pilot of the Turn X, [[AndIMustScream its nanites will keep him alive indefinitely]].
* ''Anime/RebuildOfEvangelion'': A proposed ending for ''3.0 + 1.0'' was Shinji and Gendo Ikari both [[HeroicRROD dying physically from their final battle]] but their spirits still piloting their Evangelions and the mechas, at full power, continuing to wander through space forever in constant battle.

* ''Manga/FourKnightsOfTheApocalypse'': Mortlach's magic "Duelist" allows him to seal himself and anyone who accepts a duel with him into a pocket dimension, from which neither can leave until the other is killed or rendered unconscious. Additionally, magic cannot be used in this space, only pure fighting power. InvertedTrope, as Mortlach is an antagonist who uses this against the hero Percival.

* In the last few pages of ''Fanfic/HeartlessDrich'' before the author went to work on other stuff(Let it be temporary, let it be temporary) Drich was sealed in a pocket dimension with an incomplete Naruto Physicalgod Juubi, unlike most examples it's an unstable equilibrium but it just needs to last for long enough.

* One of the many alternate endings for ''Film/FreddyVsJason'' had the pair locked in eternal battle in an arena in Hell.
* In ''Film/PiratesOfTheCaribbeanTheCurseOfTheBlackPearl'', Barbossa lampshades after he and Jack are both rendered immortal, observing they ''could'' keep fighting until the end of time. The duel itself manages to end when Barbossa becomes mortal again.
* In ''Film/DoctorStrange2016'', this is how Strange convinces the godlike Dormammu to give up on conquering Earth. He enters the Dark Dimension and brings a time-loop spell with him that activates every time Dormammu kills him. Dormammu tells Strange that he can never win, and Strange responds that he doesn't have to; he can just keep losing forever and Dormammu can just keep defeating him forever, but Dormammu will never be able to do ''anything else'' for all eternity, and since time is a new and alien concept to Dormammu, Strange's plan is more than effective. Although Strange has to suffer an untold amount of deaths in the process, Dormammu eventually gets so desperately upset being trapped in the time loop that he concedes to Strange's demands in exchange for his freedom.

* In ''[[Literature/NightWatchSeries Twilight Watch]]'', Anton, TheHero, has to go up against an uber-powerful vampire. He's given various spells by the forces of both light and darkness, as well as the Inquisition. The inquisitors' ultimate spell "Sarcophagus of Ages" encases the target and the caster in a tomb, [[AndIMustScream and they will be alive for all eternity]]. Anton doesn't use the spell this time, but it is revisited a couple novels later. The sarcophagi look like white marble domes as big as two-storey houses, drifting in nothingness of the DarkWorld. And there turn to be one or two ways to leave them.
** After finally using it, Anton figures that they will remain in the Sarcophagus until the end of time...at least he hopes the end of time will also end the Sarcophagus and their suffering. The Tiger ends up pulling him out to save itself, and Arina is retrieved in the following novel in order to save humanity.
*** Rather amusingly, Arina points out that facing an eternity together it won't be long before they turn to each other for, ahem, comfort. Thankfully it never comes to that.

* In Creator/RickRiordan's ''[[Literature/TheKaneChronicles The Red Pyramid]]'', the main characters discover that the cat goddess Bast was released from an artifact that also contained the serpent of chaos Apophis because she was losing the battle, but now that she's free she can help stop Set from completing his plans with the Red Pyramid.
* In ''[[Literature/TheSecretsOfTheImmortalNicholasFlamel The Sorceress]]'', Aoife willingly triggers this to stop Coatlicue from rampaging across the myriad worlds.
* In ''Literature/RiddleOfTheSevenRealms'', Astron can only stop Palodad from destroying the multiverse by pushing the BigBad into the flame that's tearing a hole in the daemonrealm, then [[HeroicSacrifice jumping through himself]] and pulling the source of flame in after him. It's subverted as Nimbia is able to create a new pocket-world within the Void to encase Astron, then retrieve him.
* This is how the [[TabletopGame/DungeonsAndDragons Penhaligon trilogy]] ends: Fain Flinn will fight Teryl Auroch forever to keep him from destroying Mystara.

* A variant in the Creator/DrSeuss story ''The Zax:'' A North-Going Zax and a South-Going Zax bump into each other, and each is too stubborn to go around the other, since this would require them to move slightly to either the east or west. After a brief argument the two are simply stuck glaring at each other, as years pass and other people build highways around them.
* In ''The Golden Cat'' - the sequel to ''TheWildRoad'' - the mentor character and the villain from the first novel are locked into this.

* ''Literature/TheLaundryFiles'' (by Creator/CharlesStross): In ''The Rhesus Chart'', a powerful vampire sorcerer attacks the Laundry and Angleton (an EldritchAbomination SealedInsideAPersonShapedCan) apparently performs a HeroicSacrifice to stop him, but they NeverFoundTheBody as they're sealed inside a dome-shaped protection ward too powerful to even approach. Earlier another vampire had demonstrated the use of such a ward to keep his victims alive so they can be fed upon.
* In ''Literature/TheGuardiansOfChildhood'', Pitch was originally defeated when Nightlight speared him and trapped them both in the depths of the Earth.
* In the third ''Literature/{{Mistborn}}'' novel, Vin spends some time in this situation with Ruin after she becomes the new Preservation. Both of them are theoretically so powerful that they can do almost anything you can imagine, but since they each directly oppose every single one of the other's goals, everything one tries to do the other one will immediately counteract, rendering them both functionally powerless.

* In ''Literature/HighSchoolDxD'' Numerous gods and god-level beings seal themselves away with Trihexa in order to keep it occupied and prevent it from breaking out. Unlike most examples of this trope, the large number of fighters on the good side means that not all of them have to fight at the same time, and they therefore have time to communicate with the outside world.
* In the end of ''Literature/{{Pale}}'', This is how both [[spoiler:The Carmine Exile and The Aurum Coil end up.]]

* In ''TabletopGame/MagicTheGathering'''s "Innistrad" pack, the whole plot is driven by the fact the archangel Avacyn got herself trapped in the Helvault alongside her demon nemesis Griselbrand.

* This is the origin of the Calim desert in the Forgotten Realms ''TabletopGame/DungeonsAndDragons'' setting, in the form of a never-ending duel between a djinn and efreet lord.

* A spell card called [[http://yugioh.wikia.com/wiki/Different_Dimension_Gate Different Dimension Gate]] emulates this trope in the ''TabletopGame/YuGiOh'' card game; it allows the user of the card to banish an opposing monster, so long as he banishes one of his. (However, unlike most examples of this Trope, both players get their monster back if the card is destroyed, although there are ways around this.)

* This can be [[InvokedTrope turned to your advantage]] in ''VideoGame/FTLFasterThanLight'', where if you have shields too powerful for the enemy to pierce (and they don't have missiles), you can choose not to attack and let your ship endlessly block or dodge their shots, with each block or dodge levelling up your crew a little bit. If you also have a weak weapon like the damageless Ion Cannon, you can also blast away at them for no damage, levelling up your weapons at the same time. Let the game idle for a few minutes and your crew will be maxed out in no time.
* ''VideoGame/KingdomHeartsBirthBySleep'' reveals in the secret ending that Terra is doing this with Master Xehanort as of the end of the story, both of them fighting for control of Terra's Heart. Of course, a year or so later Terra-Xehanort splits in two, his Heart becoming [[TheHeartless False Ansem]] and his Body becoming Xemnas; what they've been doing since then is anyone's guess.
** ''VideoGame/KingdomHearts3DDreamDropDistance'' indicates that both Ansem and Xemnas know about Master Xehanort, and their defeat recreated both Master Xehanort and Terra-Xehanort. ''VideoGame/KingdomHeartsIII'' reveals that Ansem's Guardian is Terra's Heartless.
* ''Franchise/{{Pokemon}}'':
** In ''VideoGame/PokemonRubyAndSapphire'', Wobbuffet was given the ability Shadow Tag, which prevents its opponent from leaving the battle (both via fleeing and via switching out). This [[UnintentionallyUnwinnable inadvertently caused this trope to become possible]]: Wobbuffet's attacks all involve its opponent attacking and Wobbuffet hitting it even harder in retaliation (and fail if the opponent does no damage), so a battle between two Wobbuffet lasts until they run out times they can use their moves and are forced to use Struggle, since they can't leave and are eternally waiting for the other to strike. However, the item Leftovers heals the Wobbuffet a small amount every turn if the Wobbuffet holds it, and since it heals more damage than Struggle causes, having two Wobbuffet fight each other one-on-one while holding Leftovers results in an endless battle, causing Wobbuffet to become the first non-[[OlympusMons legendary]] Pokémon to be banned from official tournaments. This was fixed in ''VideoGame/PokemonDiamondAndPearl'', where Shadow Tag doesn't work if the opponent also has Shadow Tag, and Struggle does 1/4 of maximum HP in damage with recoil.
*** The in-game dex entries even [[FandomNod reference this]], saying that when two Wobbuffet meet they'll engage in tests of endurance where they'll go days without eating or sleeping until one of them falls.
** The infamous "[[SuperFunHappyThingOfDoom Fun]]bro" strategy, banned in most non-official competitive circles, created an outcome like this. A Slowbro can trap an opponent with Block and then use Slack Off and Heal Pulse to not only prevent itself from fainting indefinitely but also keep their ''opponent'' from fainting [[labelnote:*]]While keeping the opponent alive is mainly just to [[{{Griefer}} troll]], it does technically have competitive merit by denying the opponent the ability to ever send in a different, more powerful Pokémon.[[/labelnote]] due to Struggle's aforementioned recoil damage. The Slowbro itself never runs out of moves thanks to using a Leppa Berry to renew its attacks periodically, and Recycle to infinitely regenerate the berry. Unless the captured foe has a way to defeat Slowbro faster than it can heal itself, it creates an endless battle where the only winner is whoever doesn't grow bored and forfeit first. Other "Fun___" strategies have been discovered, but Slowbro remains the most iconic perpetrator.
* Blizzard Entertainment likes this trope.

* The cancelled ''VideoGame/{{Ultima}} X: Odyssey'': When The Avatar sealed himself and his EnemyWithout, The Guardian, behind a wall of life to destroy them both with an armageddon spell, The Guardian managed to merge with him. They then struggle for dominance with ThePowerOfFriendship backing them up.
* Blue's ending in ''VideoGame/SagaFrontier'' appears to be him locked in an eternal battle with Hell's Lord after the portal to Hell is sealead away and the battle cuts away to a "The End" screen abruptly. WordOfGod says he teleported out, but that's not nearly as cool...
* ''VideoGame/QuestForGloryIV'' has this with Erana and Avoozl. Ultimately, the hero's reason for being summoned is to finish summoning Avoozl, breaking the stalemate in favor of the EldritchAbomination, only to free Erana who, now unbound, can banish Avoozl properly.
* ''VideoGame/FreedomForce vs. The Third Reich'': Manbot and the Wraiths of Chaos.
* In ''Franchise/StarWarsLegends'', Jedi Master [[http://starwars.wikia.com/wiki/Hoth_%28Jedi%29 Lord Hoth]] uses this method to defeat the Sith Lord Kaan; forcing Kaan to activate a superweapon that trapped their spirits, and those of their followers, in eternal conflict and torment. Until [[VideoGame/DarkForcesSaga Kyle Katarn]] released them, at least. This is all the work of Darth Bane, who sought to destroy Kaan's followers in order to remake the Sith in a superior form. [[XanatosGambit Killing Hoth and numerous other Jedi was just a bonus, and they would be dead regardless of the initial fight's result.]]
* In one of the books based on ''VideoGame/CityOfHeroes'', [[TheCape Statesman]] and [[BigBad Lord Recluse]] compare themselves to Sisyphus and the rock. Statesman wonders which one is which...
* In ''VideoGame/LostOdyssey'', this is the fate [[BigBad Gongora]] wanted to avoid, cue the 30 years long EvilPlan. Of course, in the end, making 4 powerfull immortals very pissed backfire at the end.
* As described by [[WebVideo/TheSpoonyExperiment Noah Antwiler]], ''Film/ETTheExtraterrestrial'' on the Platform/Atari2600 vs. the Player is pretty much this.

* Towards the end of ''VideoGame/BreathOfFireII'', it turns out that the sleeping, giant dragon near the village of Gate is actually a Dragon Clan member (Ryu's mother, in fact) who turned herself into that form to keep the game's HellGate closed and prevent the release of Death Evan. Slightly subverted in that you ''must'' relieve her of this task by going through the HellGate and defeating the BigBad. If you choose not to, Death Evan eventually overwhelms her defenses and bursts to the surface, resulting in a NonstandardGameOver.
** Even after Death Evan is defeated, demon gods don't just die, so the HellGate has to be closed again to guard against his future return. If you failed to unlock the flying Township, Ryu himself has to take his mother's place. If you did unlock it? [[ColonyDrop Turns out that a giant airship works just as well as a giant dragon for sealing a hole]].
* Shurelia's HeroicSacrifice in ''VideoGame/ArTonelicoMelodyOfElemia'', to seal the BigBad Mir. You get the chance to [[DefiedTrope defy]] this. If you do, both Shurelia and [[WoobieDestroyerOfWorlds Mir]] get better.
* ''VideoGame/MegaManBattleNetwork6CybeastGregarAndCybeastFalzar'' has an interesting twist: There were ''two'' great beasts ravaging the world, so they enticed the beasts into fighting ''each other'' and then blocked off the battleground as best they could so no one would interfere or get caught in the crossfire (obviously that didn't work).
* ''Franchise/TheLegendOfZelda'':
** In ''VideoGame/TheLegendOfZeldaSkywardSword'':
*** Zelda, after traveling into the past shortly after Hylia's battle with Demise, voluntarily seals herself in a crystal to maintain the seal imprisoning him. Her slumber in the crystal lasts thousands of years until the present day, when she finally awakens after Link destroys Demise for good.
*** The ''Master Sword'', the iconic weapon of the series, is this. The sword's spirit Fi takes it upon herself to seal Demise's soul within herself. Demise manages one last parting shot by placing a curse on Link and Zelda that dooms them to face an incarnation of his hatred whenever they are reincarnated. That incarnation turns out to be the series BigBad Ganon.
** In ''VideoGame/TheLegendOfZeldaBreathOfTheWild'', the only reason why Calamity Ganon hasn't completely destroyed Hyrule already is because Princess Zelda has been busy keeping him sealed inside Hyrule Castle for the past 100 years.
** Likewise, in ''VideoGame/TheLegendOfZeldaTearsOfTheKingdom'', Ganondorf was incapable of conquering and/or destroying Hyrule for eons because King Rauru had been sealing him in the Depths all that time. Unfortunately for Link and Zelda, their discovery of Ganondorf's dessicated body occurs mere seconds before Rauru's disembodied right arm falls off and the seal is broken.
* For the very last fight of ''VideoGame/DuelSaviorDestiny'' Taiga decides to invoke this one against God himself and proceeds to travel to a different dimension and do just that. Due to previously mentioned time distortions between realms, he goes on to win the fight several million times without being able to actually kill his opponent, which he knew would probably happen. Still, he manages to put a seal over God eventually, letting him return home.

* Calypso's ending in ''VideoGame/TwistedMetal 4'' has him demand the return of the ring that holds the power to grant wishes, and implicitly, the competition itself. When Sweet Tooth refuses, Calypso attacks him and wrenches the ring off his finger - whereupon the souls within it explode out. Later, a young boy finds the ring, and sees Calypso and Sweet Tooth still battling each other within it...

* An unintentional and non-heroic example happens in ''VideoGame/MiddleEarthShadowOfWar''. Sauron barely manages to avoid being defeated by absorbing Celebrimbor's spirit, but in ends up with both their spirits fighting for control over the Eye of Sauron for a very long time. But also, the fact that Celebrimbor now wants to [[FaceHeelTurn take Sauron's place]] makes this more of a ''Sealed Evils'' in a Duel. This ends up working against Sauron in the end, as it impaired Sauron's ability to invade the rest of Middle-Earth. Talion himself does this by plunging Mordor into a state of constant warfare to occupy Sauron between the timeframe of The Hobbit and The Lord of the Rings.
-->'''Elthariel''': Sometimes, stalemate is victory.
* In the backstory to ''VideoGame/BlazBlue''; Once Yuuki Terumi broke free of the geas which kept him under control as one of the Six Heroes and murdered their magician, Nine, Hakumen, their leader, arranged a trap which sealed both Hakumen and Terumi in The Boundary outside reality. Unfortunately, someone was foolish enough to let Terumi out.
** Ragna the Bloodedge gave himself his title because the previous owner of his BadassLongcoat and {{BFS}} was a hero named Bloodedge. In the distant past, Bloodedge fought the Black Beast in order to distract it long enough for humanity to learn how to use Ars Magus so they could kill it. He managed to last an entire year before the Black Beast finally killed him. Also, he was a time-travelling Ragna with amnesia, meaning Ragna unknowingly took his title from himself.
* ''VideoGame/SoulSacrifice'' is a game that lives up to its title in almost every sense of the word, such as with this trope's multiple appearances with [[BigBad Magusar]], each with a different format. At the end of [[PortalBook the writer's journal]], he explains that Magusar kept ''him'' in this loop with his immortal blood each time he was defeated until he was reduced to the form of the fleshy, deformed Librom. One of the game's endings is a reflection of this, with you reviving Magusar in an endless loop, as containing Magusar's soul would slowly erode over one's identity , same as what happened to the host you're fighting. Two mental variations of the trope occur as well, as Magusar's present host fights both against him, but in the [[UpdatedRerelease ''Delta'' expansion]], also the Gods of EternalRecurrence. After beating on Magusar enough that he considers you a threat, he lets go so you can put him to rest.
* In ''VideoGame/{{Undertale}}'''s most evil ending, Sans gets into a battle with the Fallen Child, a.k.a. [[VillainProtagonist the player character]]. Sans knows [[SensingYouAreOutmatched he can't possibly win]], but he also knows [[HeKnowsAboutTimedHits that battles in the game use turns]]. So, near the end of the battle, after everything else he's tried has failed to kill his opponent, he decides to pull out his ultimate move: ''doing absolutely nothing''. If he never attacks, he never ends his turn, and his opponent's turn will never come, therefore trapping the two of them in the battle until the end of time. Unfortunately for Sans, SurprisinglyRealisticOutcome when his BrilliantButLazy tendencies come back to bite him. By using so much of his effort and energy in the battle, he ends up falling asleep after only a few minutes of his turn, allowing the Fallen Child to kill him.
** Earlier in the game, if the player is NOT on the path to the worst ending, Mad Dummy, who is normally invulnerable to damage, threatens to do the same thing after he runs out of attacks, but he gets driven off by Napstablook.
* In [[UndeadChild Peketo's]] ending in ''VideoGame/TheBlackHeart'', Final refuses to give Peketo the titular heart because he's a dangerous psychopath. He tries blowing him up, but he reappears almost immediately, explaining that all the deals he made with the dead before he was killed have rendered him basically immortal. Faced with this, Final instead summons [[AbusiveParents Peketo's Father]] who was killed by his son at the begining of his story and because of similar deals with the dead, has ended up becoming a similar undead abomination like his son. Needless to say, neither of them is pleased to see the other so they engage in battle. Final muses that since neither of them can be killed, they are basically stuck fighting forever.

* ''VideoGame/FateGrandOrder'': In the Shimosa Province event, this briefly happens when UsefulNotes/MiyamotoMusashi and UsefulNotes/SasakiKojiro have their legendary duel. Musashi's sword style is the embodiment of "Zero" while Kojiro's sword style is the embodiment of "Infinity". The resulting YinYangClash creates a RealityBreakingParadox that draws them into a pocket dimension. The narration implies this is a timeless space where the two would fight for eternity with no conclusion. However, Musashi's master, Ritsuka Fujimaru, is present, and this manages to motivate Musashi enough to win.

* ''VideoGame/DragonAgeInquisition'': In "The Jaws of Hakkon" DLC, it is eventually revealed that the last commander of the ''original'' Inquisition, Inquisitor Ameridan, who disappeared a thousand years ago, has actually been frozen in time in a remove Frostback Basic cave, after challenging the semi-divine evil dragon named Hakkon to a duel, realizing that Hakkon is too strong for him, and [[TimeStandsStill stopping time]] around them until someone, hopefully, comes to his aid. That someone is, of course, the [[PlayerCharacter Inquisitor]], though because Ameridan has been trapped in time for so long, he dies almost immediately after being released, leaving the Inquisitor to finish the fight on their own.
* ''VideoGame/RuneScape'': Seren intended to inflict this on the armies battling the forces of the elder gods in Sentisten by using an artifact called the Eye of Het to endlessly resurrect them, and thus make sure that they could continue fighting to keep the Elder Gods from reclaiming their stollen eggs indefinitely. Zamorak however figured out what she was planning to do and destroyed the artifact and abandoned the battle, deciding he would rather he and his armies be free even though this would doom the universe.

* ''Literature/FineStructure'' has two eldritch entities from much higher dimensions dumped into our universe, because one of them was a superweapon and this was seen as the only way to stop it, and it was too strong to be battled in their higher-dimension home world.

* [[InvertedTrope Inverted]] in one ''WebAnimation/DeathBattle''. The duel doesn't keep a destructive force distracted, but is instead a multiversal apocalypse unto itself. Making [[MemeticBadass Chuck Norris and Segata Sanshiro]] fight each other was a very bad idea.
* In the final episode of ''WebVideo/CarBoys'', The Blob is doomed to forever be stuck in the outer reaches of a Time Ring, chasing Nick and Griffin in their waterproof car as they remain in the Time Ring's center for all eternity, with the boys and the reality outside the Time Ring finally safe from The Blob.

* The 90s ''WesternAnimation/SpiderManTheAnimatedSeries''
** ComicBook/CaptainAmerica and the Red Skull found themselves trapped in an energy vortex while in the middle of a battle. They are freed, but Cap later pulls Red Skull back into the vortex, so they find themselves in the same situation as before. Eventually, Electro is thrown into the vortex as well.
** From the same series, a sort-of-reformed Venom ends up jumping into a portal along with his EvilCounterpart, Carnage, and since the portal closes after that, it's implied that this will be their fate. A sort-of SequelSeries saw them on another planet/dimension, though.
*** The Carnage symbiote (possibly not the original) escaped at the conclusion of the original series. What happened to Kasady and Venom is never discussed.

* One episode of ''WesternAnimation/TheFairlyOddParents'' had a variation on this. Timmy wished [[BabysitterFromHell Vicky]] wasn't his babysitter, and she became mayor of the city instead. Subsequent attempts to remove Vicky from power through wishing instead resulted in Vicky gaining even more power, up to the point where she became a galactic conqueror. In the end, Timmy realized [[ItsUpToYou it was up to him]] to prevent any of these from happening, and wished her to be his babysitter once again.
** As for a closer example, there is an episode where Timmy wishes both of his parents were the best surfer. Due to the impossibility of two people being best at the same thing at the same time, they get locked into an eternal surfing competition known as Wish Limbo...limbo...limbo...limbo...However, it's broken when they find something that's more important to them than surfing, Timmy, who is attacked by the Kraken he wished up to try and scare them out of Wish Limbo...limbo...limbo...limbo...

* In the season 2 finale of ''WesternAnimation/{{Wakfu}}'', this seems to be the fate of Goultard the Barbarian and Rushu, king of the Shushus, after the former drag his opponent back to his demonic realm. Indeed, the "Where Are They Now?" epilogue shows them still facing off through Igor the Shushu mirror. This is then subverted in the specials, where it's revealed that Goultard ''eventually'' (within the span of [[TimeSkip six years]]) won hands-down, and [[HellHasNewManagement is living comfortable]].
* In the backstory for ''WesternAnimation/TheLegendOfKorra'', the GodOfEvil Vaatu was kept contained by a centuries-long duel with the light spirit Raava. This fell apart when Vaatu tricked [[PrecursorHeroes Avatar Wan]] into thinking that Raava was a bully that needed to be taken down a peg.
* In the season 1 finale of ''WesternAnimation/StevenUniverse'', "Jail Break," Lapis Lazuli agrees to fuse with Jasper and forms Malachite. Malachite is then dragged into the ocean by Lapis working against the fusion, and Lapis uses her water powers to create chains made out of water, effectively trapping her and Jasper in a duel at the bottom of the ocean for as long as she can survive. Subverted later on when Jasper manages to come out the victor enough to force Malachite back to the surface and break loose of the chains (along with Malachite's ''own'' will gaining some level of control), though shortly after this Malachite fought the Crystal Gems and was forced to defuse back into her components.

* The ''WesternAnimation/ChalkZone'' TVMovie "The Big Blow-Up" featured a temple of Inflatermaus, a swarm of insectoid creatures that were able to infect the inhabitants of [=ChalkZone=] with a fatal disease called Balloonemia. Before Rudy Tabootie re-imprisons the swarm behind a glass wall with his magic chalk, it is revealed that [=ChalkZone=]'s long lost ruler King Mumbo Jumbo had been keeping the Inflatermaus swarm at bay all these years.

* ''WesternAnimation/JusticeLeagueDarkApokolipsWar'' ends this way. Raven and Constantine of all people come up with the plan to defeat Darkseid once and for all by releasing Raven's demon father Trigon from his mystical prison inside her mind. Cyborg, in his DyingMomentOfAwesome, traps planet Apokolips--along with Darkseid and Trigon--in the empty void between dimensions where they can battle it out for all eternity. The kicker? Trigon is ''completely ecstatic'' to finally have a WorthyOpponent and tells the remaining heroes, "Go, unless you would fight me for the right to destroy him." He also thanks his daughter for such a thoughtful "parting gift."

* As described by [[WebVideo/TheSpoonyExperiment Noah Antwiler]], ''Film/ETTheExtraterrestrial'' on the UsefulNotes/Atari2600 vs. the Player is pretty much this.

* The ComicBook/JusticeSocietyOfAmerica did this when they fought the Norse Gods in ''ComicBook/LastDaysOfTheJusticeSociety'', to prevent UsefulNotes/AdolfHitler from destroying the world with TheSpearOfDestiny. {{Justified|Trope}} as the battle was Ragnarok, which ended like this.
* Once, after Doctor Doom came within an inch of wiping out the ComicBook/FantasticFour, Reed decided the only way to keep his family safe from Doom for good was to trap the two of them in an inescapable pocket dimension. Knowing the team would never allow him to do this, Reed tried to distract them and push them away emotionally, but they managed to stop him anyway (unwittingly letting Doom escape). The kicker? Doom was ''already in Hell'' when Reed resorted to this -- with Doom's record, he didn't trust the devil to hold him.
** and he was right! The comic shows Reed interrupting Doom in hell just as Doom was beginning to put a plan in motion.

* In the ''[[ComicBook/TheTransformersMarvel Transformers Generation 1]]'' comic books, this is how the planet Cybertron and the [[PlanetEater planet-eater]] [[GodOfEvil Unicron]] came to be -- he and Primus were elder gods who battled across several planes, with the single-mindedly destructive Unicron winning the battle. As a last resort, Primus led Unicron from the astral plane into what is our dimension and directly into two metal asteroids, trapping both of them for eternity. While Primus turned his asteroid into the planet Cybertron, Unicron managed to turn his asteroid into a [[EldritchAbomination transforming planet-sized robot.]]
* In Creator/MarvelComics's what-if of their crossover ''ComicBook/AtlantisAttacks'' (in ''ComicBook/WhatIf'' v2 #25), Set the Serpent God succeeds in freeing himself from interdimensional exile and returns to Earth, killing most superhumans and converting the rest (as well as regular humanity) to serpent people. One by one the remaining heroes and villains fall, and all hope seems lost, until ComicBook/{{Quasar}} arrives on the scene, having just escaped Set's dimension (where he'd been lost since the Serpent God escaped). He's been granted the ComicBook/CaptainUniverse power, which combined with his Quantum Bands to make him Set's equal. He opens the recently deceased Comicbook/DoctorStrange's [[AmuletOfConcentratedAwesome Amulet of Agamotto]], using it to pull them both into a pocket dimension where the two of them will battle forever. Unfortunately, although Set has been removed from the equation, [[DownerEnding he's had time to reproduce...]]
* Another example from Marvel - after [[ComicBook/TheMightyThor Odin]] got KilledOffForReal in a battle with Asgard's arch-enemy Surtur, their battle continued on the doorstep of the afterlife. Every day Surtur tries to reach a part of his spirit that will allow him to revive in the real world, and every day Odin kills him and then dies from terrible wounds, just for their injuries to disappear by the next day, so that their struggle may continue until the end of time. Odin doesn't mind though, seeing this fate as an atonement for his old misdeeds and mistakes.
** This actually happened several times. If Odin is not around it's a safe bet that he is sealing some evil in a duel. The most common of those evils is Surtur, but he also did this with Cul for example, albeit in a slightly more cultured way as [[SmartPeoplePlayChess they played]] [[TheChessmaster chess]] for "eternity" (which lasted from the end of Comicbook/FearItself to Comicbook/OriginalSin). To be fair this ''is'' a fairly reasonable way to keep the nigh omnipotent [[PhysicalGod sky-father]] from breaking the story.
* During the prestige format run of ''ComicBook/LegionOfSuperHeroes'', the Legion finally "defeated" the Time Trapper (the AnthropomorphicPersonification of the Cold Universe cosmic model) by unleashing the Infinity Man (the AnthropomorphicPersonification of the Cyclical Universe cosmic model) on him. The two end up locked in eternal combat with each other.
* An Elseworlds posits that Franchise/{{Batman}} and the Joker will be fighting each other in one form or another for eternity. ''WesternAnimation/BatmanBeyondReturnOfTheJoker'' also supports this notion, at least until Tim kills him.
* This is how Palpatine is ultimately defeated in ''Franchise/StarWarsLegends'': Empatojayos Brand sacrifices himself so he can carry Palpatine's spirit away from the universe and in the custody of every Jedi who has ever lived, never to be resurrected again. He doesn't have to undergo FateWorseThanDeath himself, fortunately, but the effort of carrying away a spirit of pure evil does cause his own spirit a great deal of suffering.
* An issue of the Dark Horse Franchise/{{Godzilla}} comics featured Gekido-Jin, an invincible demon who is imprisoned [[TakenForGranite in a statue]] by a warrior whose soul fights his soul for all eternity. When Godzilla decides to go sightseeing on the (still inhabited) island Gekido-Jin is imprisoned on, a minor character sacrifices himself to free the ancient warrior from his eternal battle and let Gekido-Jin live long enough to drive Godzilla off, at which point the man who sacrificed himself takes up the spirit-duel with the demon.
* In the fourth issue of ''ComicBook/GodzillaInHell'', Godzilla finds himself trapped in a walled city replica of Tokyo in the afterlife, eternally fighting King Ghidorah and Destroyah, as whenever any of them are killed, they immediately come back to life. Godzilla tries to destroy the wall around the city, but finds that his atomic breath isn't able to damage it. He manages to destroy the wall by tricking Destroyah and King Ghidorah into firing at the same spot as him, which is enough to break through. When he does, King Ghidorah, Destroyah and the city immediately vanish.
* At the end of the ''Crimson'' comic, one half of the BigBadDuumvirate, the king of dragons, who it's implied can never be truly killed (and thus it's implied could otherwise always recreate [[OurDragonsAreDifferent the dragon race]] in time), is dealt with this way when it and the current {{reincarnation}} of Saint George (yes, that one) are trapped in a PocketDimension to fight each other forever. Actually subverted in that {{God}} intervened, so that the dragon king would be FightingAShadow for eternity, while the ''real'' Saint George, after centuries of service culminating in a HeroicSacrifice, is finally taken to [[{{Heaven}} his final reward]].
* While not exactly "sealed", it's revealed in ''ComicBook/SonicTheHedgehogArchieComics'' that the Xorda, aliens that eradicated most of the humans when Mobius was known as Earth, and [[VideoGame/ShadowTheHedgehog Black Arms]], aliens seeking to feast on Mobius' population, are locked in a vicious war with no end in sight over their claim of Mobius.
* ''ComicBook/NemesisTheWarlock'': The final arc concludes with Nemesis stopping Torquemada from activating his "[[WeaponOfMassDestruction Final Solution]]" (a bomb designed to exterminate every alien and all humans who came into contact with an alien) by drawing the explosion into both himself and Torquemada, who is also vulnerable after Nemesis scratches him with his claws. Nemesis and Torquemada merge with the Blitzspear into a single entity which roams the cosmos for billions of years into the future.
* The Shaggy Man is a mindless beast with incredible strength and seeming immortality. In its first appearance, it was finally defeated when Franchise/TheFlash suggested to its creator Dr. Andrew Zagarian to create a second Shaggy Man. While the two creatures fought, the Justice League sealed them into a deep pit. Of course, villains eventually found the pit and freed them.
* In the ''ComicBook/JusticeLeagueOfAmericaTowerOfBabel'' storyline, the League are up against [[BetrayalInsurance contingencies]] created by Batman to incapacitate them in some way should they ever go rogue. As a proud warrior who would never give up a fight against any opponent, Franchise/WonderWoman is trapped in a simulation where she fights an opponent that's equal to her in every way, and the fight would last until she dies of exhaustion.

* In ''Comicbook/{{Spawn}}'', after God and Satan, [[GodAndSatanAreBothJerks two horrible entities]] with a vicious SiblingRivalry, bring about the End Times way ahead of schedule, they are left in a barren world and decide to fight each other. However, it was only a pocket dimension, as their creator, the Mother of Existence, enabled Spawn to press the ResetButton and remake Earth in his image, while banishing the two 'deities' away from it.
* ''ComicBook/AstroCity'': When American Chibi realizes that her presence in the real world is what allows the [[SealedEvilInACan King-In-Chains]] to exert its influence beyond Ibbopolis, she volunteers to seal herself in their PocketDimension to keep it trapped. Chibi and the King remain locked in a never-ending battle as a result.

* ''WesternAnimation/AdventureTime'' has Goliad, Princess Bubblegum's genetically engineered heir who'd gone mad with power and tried to take over the Candy Kingdom with her mind control powers, ultimately defeated by Stormo, another Candy Sphinx created using Finn's DNA, sacrificing himself by locking her in a psychic duel with himself. Nobody thinks to just kill or knock out Goliad now that she's incapacitated.

** [[http://www.scp-wiki.net/roget-s-proposal Roget's Proposal]] is based on the principle of sealing dangerous [=SCPs=] using other dangerous [=SCPs=] that counter them. For example, [[http://www.scp-wiki.net/scp-140 SCP-140]] (a history book that extends itself by absorbing any writable fluid and, when no more fluid is available, retcons history to match its contents) is sealed by [[http://www.scp-wiki.net/scp-505 SCP-505]] (a pen that produces an endless quantity of ink).

* ''WesternAnimation/AdventureTime'' has Goliad, Princess Bubblegum's genetically engineered heir who'd gone mad with power and tried to take over the Candy Kingdom with her mind control powers, ultimately defeated by Stormo, another Candy Sphinx created using Finn's DNA, sacrificing himself by locking her in a psychic duel with himself. Nobody thinks to just kill or knock out Goliad now that she's incapacitated.
** In the original storyboards for "The Lich", Billy tells Finn about the Crystal Citadel, a prison for the multiverse's most dangerous criminals. He also says that Finn's birth father was unjustly imprisoned there and has been battling the criminals held there ever since.
*** This has been both confirmed and refuted in canon, as Finn's father WAS imprisoned there, but he's actually a criminal just as bad as the other inmates (so far).

* In ''LightNovel/HighSchoolDxD'' Numerous gods and god-level beings seal themselves away with Trihexa in order to keep it occupied and prevent it from breaking out. Unlike most examples of this trope, the large number of fighters on the good side means that not all of them have to fight at the same time, and they therefore have time to communicate with the outside world.

** In ''VideoGame/TheLegendOfZeldaSkywardSword'', Zelda, after traveling into the past shortly after Hylia's battle with Demise, voluntarily seals herself in a crystal to maintain the seal imprisoning him. Her slumber in the crystal lasts thousands of years until the present day, when she finally awakens after Link destroys Demise for good.
*** Furthermore, it's revealed that the ''Master Sword'', the iconic weapon of the series, is this. The sword's spirit Fi takes it upon herself to seal Demise's soul within herself. Demise manages one last parting shot by placing a curse on Link and Zelda that dooms them to face an incarnation of his hatred whenever they are reincarnated. That incarnation turns out to be the series BigBad Ganon.

* The ending to ''VideoGame/Doom64'' has shades of this; after once again entering Hell to stop the Demons from attacking humanity, the Doom Marine decides to stay there for good, in order to prevent them from rising up yet again. ''VideoGame/DoomEternal'' deconstructs this as fighting against demons in Hell for a long time eventually wore away at Doomguy's sanity, and he was a madly raving wreck by the time the Night Sentinels found him.

* In ''VideoGame/TheElderScrollsVSkyrim'', after inadvertently waking the Dragon Priest, Morokei, in the depths of Labyrinthian, Savos Aren contained him by enthralling his dead colleague's spirits in an eternal magical duel, preventing Morokei from being unleashed upon an unsuspecting Skyrim. He feels guilty about it to this day; the nature of the spell meant he couldn't sacrifice himself in their place.

* ''Manga/InuYasha'': Five hundred years before the story's main feudal setting, the most powerful {{miko}} and the most powerful {{youkai}} of the era fought. Unable to defeat each other, the {{miko}} performed one last desperate spell that trapped their souls for all eternity, in a manner that ensured their eternal battle had minimal impact on the world. The two original souls are almost spent, which threatens the Shikon no Tama's continued existence, so Naraku offers it the chance for eternal survival: replacement of the original souls with his and Kagome's. Kagome selflessly wishes for the jewel to cease existing, thereby ending the threat and allowing the original souls to find peace.

* ''Series/StarTrekTheOriginalSeries'': In the episode "The Alternative Factor", Sane!Lazarus asks Captain Kirk to imprison him and his [[OmnicidalManiac evil, normal matter counterpart]] in a time corridor, where both will remain fighting in a form of living death for all eternity. Since refusing to do this would put the universe at risk, Kirk reluctantly agrees to carry out this plan. FridgeLogic kicks in because, unlike almost every other example of this trope, Lazarus is not a god-like being who can only be opposed by his opposite half, he's just an ordinary man with slightly better advanced technology. There's nothing to stop them from simply shooting the evil Lazarus, or at least handcuffing him to a pipe.

* In the season 5 finale of ''Series/{{Supernatural}}'' Sam invites [[TheDevil Lucifer]] to possess him, then trying to keep control of his body long enough to jump into the Can they have no chance of getting Lucifer into otherwise. Sam does end up jumping into the cage, with [[ArchangelMichael Michael]] (In [[CainAndAbelAndSeth Adam]]) falling in with him.

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* In the final episode of ''Series/KikaiSentaiZenkaiger'' has Kaito end up locked in a mental battle with [[spoiler:the creator of worlds]] to decide the fate of the multiverse. The two of them can't actually defeat each other and so they decide to settle the battle with Rock Paper Scissors so that they won't end up fighting each other forever.