Not all manufacturers of Sealed Evil in a Can use child-resistant caps.
Sometimes the Sealed Evil in a Can doesn't escape by itself, nor is it released by an Unwitting Pawn, but is deliberately set free by a villain (or hero). Let's call him Bob. Bob usually thinks he can control the sealed evil, or bargain with it, expecting to trade on a certain level of gratitude on its part since he was the one who freed it (or in extreme cases, resurrected it).
The Sealed Evil in a Can will inevitably turn on the one who freed it sometimes sooner, sometimes later. In many cases, it turns out to have no understanding of loyalty or gratitude at all. Bob may end up being killed on the spot, or he may be enslaved by the sealed evil bonus points if the one who freed it sought to enslave the evil themselves. The sealed evil may make a bargain that it has no intention of honoring (or it may promise Bob he will be rewarded "as he deserves"... guess what he deserves?). Or it may simply refuse to obey him. If he's very lucky, Bob may merely be forced to become the newly-unsealed evil's minion on pain of death. In any case, if Bob was the Big Bad before, he was really just a Little Bad; the formerly-sealed evil is the true Big Bad. In the event that Bob survives, this is a leading cause of Enemy Mine twists, since Bob now must seek any allies he can find to deal with the evil that he unleashed.
In some cases, the sealed evil has further need of Bob; perhaps it is in some way at his mercy, or it needs him to perform a task that will free it fully, or it is just feeling sadistic. No matter what, it will always manipulate Bob into doing its bidding, stringing him along with promises of power and/or wealth, before finally pulling a Did You Actually Believe...? on Bob the moment it no longer needs him. After all, you certainly don't get rewarded just for doing what you're expected to do, especially after You Have Outlived Your Usefulness. Other times, the evil being may ask Bob what exactly he expected after releasing an evil being.
This goes triple for anyone attempting to activate a hero's Super-Powered Evil Side. Unless you are The Emperor and would already be stronger than them, just remember: once they're evil, they no longer have any qualms about killing you.
If you're a villain, take note: Sealed evil should not be released unless you expect it to betray you. Also, it should be kept away from children under 3 as they have small parts and it may not choke on them.
This goes both ways, as sometimes Bob is the Sealed Evil in a Can and the villain he's trying to dupe into releasing him is the one who's not a toy, and as such will brutally subjugate Bob the moment he underestimates the releaser.
This trope often overlaps with Deal with the Devil, as bargaining with a force of evil always screws over the client in the long-run.
Eat the Summoner is a Sub-Trope. See also This Is Your Brain on Evil. If Bob created the evil in the first place, it's a case of Turned Against Their Masters. When the evil actually is a toy, it may coincide with My Little Panzer, Killer Rabbit, or Sealed Evil in a Teddy Bear. If the Evil in question is a Greater-Scope Villain, expect the lesson to be particularly painful. Contrast Holy Is Not Safe, where concentrated goodness is similarly threatening, Hijacking Cthulhu, where the "lesser" evil really does make a toy of the "greater" one, and With My Dying Breath I Summon You, where the summoner dies before the evil does anything to him.
- A lot of Hellboy's enemies seem to think that they can use the Right Hand of Doom and Ogdru Jahad for their own ends (even Hell), while it is implied that they would merely destroy all of reality. It's a recurring theme among others who don't try to use the Ogdru Jahad. Sorcerers and witches who traffic with demons die painful deaths and are sucked down to Hell. The Fair Folk and witches revive a mad Nimue to wage war on humanity. The results are far more horrifying than anyone expected.
- Sebastian Shaw, foe of the X-Men, helped to develop and secure funding the mutant-hunting Sentinels, figuring if he builds them instead of someone else, he can instill a Restraining Bolt to keep them from recognizing him as a mutant. This led to the Days of Future Past, a Bad Future where the Sentinels Turned Against Their Masters and waged a genocidal war on mutants everywhere.
Another Hellfire Club member didn't fare much better. Mastermind learned The Dog Bites Back when he twisted Phoenix into Dark Phoenix.
- The Phoenix Force is the big topic of Avengers vs. X-Men. The Avengers are on this side of the trope thanks to Wolverine while Cyclops believes the Force will bring back mutantkind, which has been largely depowered. When five mutants gain control of the Phoenix Force, the Avengers grab hold of the Idiot Ball as they continue to espouse this trope.
- Invoked in Superman story Kryptonite Nevermore. In order to cure Superman's illness, Wonder Woman's mentor I-Ching performs a dark magic ritual. He is aware of the risks and the foolishness of playing with black magic, but he thinks there is no other way to help the Man of Steel.
- In Superman/Supergirl story War World, alien overlord Mongul appropriated a star-sized weapon-satellite built by a race of warmongers who passed away right after building it. It never occurred to Mongul that both events could be linked and Warworld might bring death to its owner.
- In Supergirl story arc Bizarrogirl, Bizarro Lex Luthor sent a signal into the core of the planet, hoping to find someone to come out and help him kill Bizarro, but the signal went in the opposite direction and attracted a planet-eating monster.
Supergirl: What happened to Bizarro World, Lex? And what is the Godship?
Bizarro Lex: Godship am Big Bad. And it came because of me. Me was trying to find worstest way to hurt Bizarro #1, my worstest enemy, so me sent signal into core of the planet, hoping to find someone to come out and help. But signal went opposite direction into space and it attracted—
- In one Witchblade/Tomb Raider crossover comic, a haughty socialite goes to great lengths to summon the goddess Bastet, without ever considering whether she could actually control a divine being. When she wishes to be kept out of prison, the goddess remarks that this is easily arranged, and sics a pet lion on her.
- Doctor Strange used the power of the demonic entity Zom to bolster his magics on at least two occasions. Both times the power used him far more than he used it, and after the second time he renounced both it and the mantle of Sorcerer Supreme. He didn't get his title back until years later, once he'd demonstrated that he could use dark magic without letting it get out of his control and without hurting anyone else.
- In Siege, Norman Osborn and Loki realize just how badly they underestimated The Sentry/Void's power and evil.
- In Batman RIP, when the Black Glove attempts to use the Joker to finish off Batman. Joker himself tells them that they haven't come nearly as close to beating Batman as they think, and that they can't control the Joker himself. Later, after the dust has settled, Batman's won, and the Black Glove members have gone home to hide behind their money, Joker murders them all.
- John Constantine's first rule of magic: Never summon up something you can't put back down. He learned this the hard way in Newcastle in '77.
- Pretty much Once per Episode in Vampirella, someone will make a Deal with the Devil, only to realize too late that they got more than they bargained for.
- In New Suicide Squad #1, Amanda Waller loses full control of the team of supervillains and has to share it with Victor Sage. Unlike Waller, however, Sage treats the Squad (sorry, Task Force X) like his personal fantasy league, introducing stupid changes like renaming the team Task Force XL, hiring the extremely mercenary Deathstroke without the requisite Explosive Leash and putting together Harley Quinn (who recently gave up on the Joker for good) and Loony Fan Duela Dent (the self-proclaimed "Joker's Daughter"), in a bid to draw the Joker out of hiding so that they can put him on the team. Deathstroke betrays the team five minutes in, Harley brutally beats up Duela, and due to Sage's incompetence, Deadshot's aim is crippled. Waller chews him out for his colossal ego and absolute lack of foresight.
- 2000 AD:
- Judge Dredd: During the Day of Chaos, a Sov sleeper agent releases the three remaining Dark Judges (the fourth, Judge Death, is trapped in Hell at that point) to add to the escalating clusterfuck in Mega City One. The two spies who give the undead monsters new bodies are the first to die.
- Tales of Telguuth: A man is blackmailed by a demoness to free her demon husband by finding the tomb where he was locked up by a powerful wizard (which she is barred from entering herself) and removing an enchanted ring from his hand. He tries to remove the ring by cutting off the sleeping demon's finger, finding out that he can control the demon as long as the Ring of Power binding him stays attached to the finger. He forces the demon to kill his own wife because she had planned for the man to be eaten by her husband, then uses him to take over the nearby kingdom. This backfires when the demon refuses any further commands because the ring has slipped off the by now shrunken finger, and tears apart his would-be master.
- In Hack/Slash, a company named Ceutotech captures various Slashers and tries studying them, with the intend to replicate their Healing Factor and adapt it for cosmetic purposes. Predictably, the Slashers end up escaping, wreak havoc in the facility and Ceutotech's head Emily Christie gets turned into a Slasher herself for her trouble.
- In Athena Voltaire and the Immortal Power, Major Klimt and Herr Faust (a Meaningful Name, that) really don't know what they're doing, and Athena thinks the smart response would be to just sit back and watch the fireworks.
Athena: Let me get this straight... Ada wanted you to perform a ritual that no one understands, and, if it works, no one has any idea what it does? On top of that, even if you don't perform the ritual, she's prepared your understudy to give it a try even though he knows even less about it than you do. Call me crazy, but I say we just let 'em try.
- The Sandman opens with Dream being torn out of his realm and imprisoned by a group of magisters who thought they could summon Death as a neat trick.
- Runaways loves this trope:
- In the original series, Alex's secret plan is to bring about the end of the world in the mistaken belief that the Gibborim will reward his family more lavishly if he sabotages the rest of the Pride. This theory turns out to be false, and the Gibborim straight up kill him.
- In the second series, the New Pride tries to renew the original Pride's efforts in order to resurrect Alex. They fail, thankfully, but not before killing Gert. And then Chase tries to make his own deal with the Gibborim, offering his own life to sustain them in exchange for Gert's resurrection. His plan is so poorly conceived that the Gibborim nearly kill the entire team.
- Another arc sees an old man accidentally summoning a monster in an attempt to bring back his dead wife.
- In JLA: A League of One, a bunch of goblins, who have become peaceful and complacent, find the sealed tomb of their mistress, the colossal dragon Drakul Karfang, and wake her up in a bid to regain their importance. First thing she does upon waking up is to taint them into mindless monsters and send them off to assault the towns above.
- Sonic the Hedgehog/Mega Man: Worlds Collide: While held captive, Dr. Light reminds both Eggman and Wily of the numerous times the two have toyed with forces they thought they could control, only for it to blow up in their faces and result in Sonic and Mega Man having to save them from their own stupidity, stating that their plans to rewrite reality with the Genesis Wave will undoubtedly end the same way:
Dr. Light: Albert... You thought you had complete control of Ra Moon, Gamma, King, The Stardroids, Roboenza, and Bass? You've toyed with things you cannot handle for years, and Mega Man had to save you from yourself. And from what I've heard, you're no different, Doctor Eggman. Chaos, The Ark, Emerl, The Time Eater? If not for Sonic, you wouldn't have a world to conquer.
- In Justice League vs. Suicide Squad, Max Lord obtains the Heart of Darkness, takes possession of the powered members of the Justice League, then proceeds to take over the United States. When he brings in Amanda Waller to show her the fruits of his labor, he boasts that he has everything under control, even using a tattoo to protect him from the gem's owner. However, when Waller shows Max that he's sent the world into chaos, Max is horrified. Then, Eclipso takes over his body.
- Satan's Hollow revolves around a Satanic cult trying to open a portal to hell through Human Sacrifice. In the backstory their previous leader messed up the ritual when his last victim escaped, and was turned into a Living Shadow by the Devil as punishment for his failure. The epilogue shows that the same fate has befallen his partner-in-crime.
- Arawn: Anyone who thinks they can somehow control the Cauldron of Blood is a misguided fool. It may offer its current owner great power, but it's always on the look-out for a new Master and its only real goal is to acquire as many souls as possible for itself to feast on.
- The villains of both Batman / Alien crossovers believe they can manipulate the xenomorphs for their own ends. It ends exactly as well as you think for them. Special mention should be made of the one who hybridized Batman's Rogues Gallery and xenomorphs, counting on their human instincts to protect her. Then she made a Killer Croc hybrid...
- Robin Series: The General teams up with Toyman in order to pull off a heist, not realizing that Toyman hates kids, is plotting to kill him, and that his own obnoxious behavior isn't helping things any.
- Ultimate Vision: Everybody, from the Vision to his fellow scientists, tells Tarleton that toying with the Gah lak Tus unit is a massively bad idea. He refuses to listen and the module nearly destroys the world.
- Wonder Woman:
- Wonder Woman (1987): Thomas Randolph keeps finding more and more questionably ways to increase his magical power, which eventually warps him into an inhuman monster and kills him while he kills Artemis.
- Wonder Woman (2006): Ares even warns Alkyone that those who call him up to make deals never get what they want out of it. She doesn't listen and greedily accepts Ares' "gift" of a daughter; Genocide. This does not work out well for her.
- Immortal Hulk:
- General Fortean thinks it's a good idea to dig up Rick Jones's corpse and merge it with the remains of Abomination to create a mindless Hulk-killing creature. Later on, he goes so nuts he thinks putting himself in there is a good idea as well. It turns out it's enough to drag his soul down to Hell.
- Corrupt Corporate Executive Darrio Agger thinks not only decides to pick a fight with the Hulk, he hires Xemnu to brainwash everyone into forgetting him. Xemnu can only do this by being fed a steady diet of people. So what happens when Agger inevitably runs out of people? Xemnu eats him.
- The My Little Pony: Friendship Is Magic fanfic Whispers implies that Princess Luna transformed into Nightmare Moon by intentionally tapping into evil magic out of bitter jealousy, apparently overestimating her ability to handle it.
- Child of the Storm has the Darkhold, an incredibly powerful book of black magic, which can grant the user all sorts of powers. There's just one small problem: using it opens the reader up to possession by the book's author, the Elder God of Chaos and Black Magic Chthon, since it's basically his Soul Jar. Oh, and it's sentient, and returning its master is its sole goal.
- Dark magic in general works like this; even if used with the very best of intentions and in total ignorance, it will drive you insane and turn you into a twisted monster, unless you either have an artefact that blocks the side-effects, or - in very, very rare instances - you've mastered the ability to use it without being corrupted. It is explicitly described as the last test of an Apprentice Sorcerer Supreme, and one that many Apprentices have failed, leading to some of the worst and most powerful Dark Lords and Ladies in history.
- While not evil, more incredibly volatile, using Phoenix Fire is usually a very, very bad idea. Unless you have absolute mental discipline and can keep your emotions in check, it will corrupt you and turn you into a Humanoid Abomination bent on destroying everything (one previous example destroyed a galaxy and was only getting warmed up). As a result, hosts for that power are chosen extremely careful.
- Played for Laughs during Theory of Chaos:
Chaos: How is it that I'm supposed to do your schoolwork? I'm CHAOS!! Not some sort of encyclopeadia!
- In the Danny Phantom fanfic Facing the Future Series, Clockwork lampshades Vlad's many attempts to gain power beyond his control in his "The Reason You Suck" Speech to him. Vlad is currently trying to steal Clockwork's power over time. Subverted in this instance because Clockwork beats him instantly before Vlad can do any damage.
Clockwork: "Vortex the Infi-Map Pariah Dark. Time and again, you've tried to seize control of powers beyond your meager understanding and time and again, you've met with failure. And now you come into my domain with all the forethought of a teenager looking to steal a car for a joyride and brazenly declare that you will take MY power from ME?"
- Showing that he learned absolutely nothing from that total failure, he then promptly proceeds to try and use a Fenton device to steal the power of Dan, Future Danny and Future Sam. Not only does he get electrocuted multiple times trying to rewire the device, he ends up healing Dan of all the damage the future heroes had managed to inflict on him!
- In Tails of the Old Republic, Tails thinks back on the occasions Eggman fell into this trap
- In Yognapped, Peva frees Herobrine from beneath the bedrock layer, planning to partner up with him and destroy Minecraftia. Herobrine briefly considers this, before scorching Peva's hand, completely obliterating his gathered troops, and going off to fulfill his own agenda.
- Rosario Vampire: Brightest Darkness: Fairy Tale has a very bad habit of trying to take control of powerful beings and artifacts for their own purposes. While they may have no problem controlling them at first, more often than not, it blows up in their faces in the end.
- In Act II, they manage to get their hands on Apoch and Astreal's original summoning spell and use it to create their own personal Clone Army of slaves. By chapter 51, the clones have snapped under the constant abuse and turn on them, helping Tsukune and co. put an end to Fairy Tale's Ashton City branch.
- In Act III, Kiria hopes to harness Tsukune's inner ghoul, planning to infect it with Blackheart and sent back in time to the Battle of Kahdaln to rewrite history in favor of the monsters. In chapter 52, when Tsukune deliberately unleashes it, the ghoul promptly pounces on Kiria and both dismembers and disembowels him with his bare hands while Kiria tries in vain to reason with it. In a double-dose of this trope, it's more-or-less general knowledge that ghouls are nothing but animals who are only concerned with killing everything they see, and Tsukune's ghoul, despite having its own personality and conscious mind, is no exception.
- In Act VI, Gyokuro makes a clone of Luna, enhanced with a quadruple overdose of improved Blackheart, named Discord, intending for it to be a new Alucard under her control. According to the Act VII preview chapter published at the very end of Act VI, when Discord is completed, it will rage out of control and destroy the entire universe.
- In Prison Island Break, Shadow the Hedgehog doesn't like being told what to do. His insanity results in what Knuckles jokingly refers to as 'Shadow Logic' (a combination of Insane Troll Logic and Poe's Law), under which he would start a forest fire to light a cigarette. On top of that, he uses poorly conceived gambits that succeed, but with horrible knock-on effects.
- This Gravity Falls/My Little Pony: Friendship Is Magic crossover comic involves Starlight Glimmer making a deal with none other than Bill Cipher. It's pretty easy to guess what happens afterwards.
- Zigzagged in the The Legend of Zelda fic Wisdom and Courage. Veran finds Majora's Mask and successfully gains its power under her control, but it turns out that Majora only allowed her to do so of its own free will, admitting to Link during their Battle in the Center of the Mind during the final showdown that it had planned to betray Veran and seize control of Hyrule for itself all along.
- Veran actually pulls this off twice. During the final battle, she genuinely believes she can take control of Fierce Deity Link, only to be proven wrong when Link breaks free of her control and defeats her. Doubly do, since Veran had actually fought the Fierce Deity previously and knew that it could potentially defeat her.
- Inverted in Kingdom Hearts fanfic Stygian Solace. Due Riku's unavailability as a host, Ansem, Seeker of Darkness gets the next best person Kairi. However, this results in the creation of Yami as Ansem's heartless is slowly purified by Kairi's pure heart.
- Time Lords and Terror: Hydia spends the entire story trying to free the S'Muz from its can so that she can use it to destroy her enemies. Naturally, she ends up being the first thing it kills.
- A Storm of Chaos: A Doctor Whooves Adventure: Borusa, the true Big Bad, steals Discord's statue and frees him, just so that he can experiment on him for the secrets of immortality. When the Doctor frees Discord during the climax, he proceeds to torture Borusa before turning him to stone.
- Neon Genesis Evangelion: Genocide:
- Gendo and Ritsuko allows the Emerald Tablet, a mysterious and powerful A.I., to operate without safety protocols in order to allow it to create new Angels for the Evas to fight in order to convince the UN of the necessity of keeping NERV around, with the intention of buying Gendo more time to set up his version of Third Impact. They both manage to underestimate the Tablet's capacity for self-learning, leading to it becoming self-aware and developing a God-complex as well as homicidal tendencies, resulting in a lot of unforeseen damage and Ritsuko must eventually admit to Gendo that the situation is rapidly spinning out of their control.
- SEELE later forms an alliance with the Emerald Tablet and gives it control of a series of Kaworu clones and the Mass Produced Evangelion series believing that they can control it. It quickly ends up betraying them and kills their pawn almost right away.
- Guardians, Wizards, and Kung-Fu Fighters:
- Lothar willingly takes on the Ninja Khan mask to destroy the Guardians and avenge Raythor. This backfires horribly, as the Oni inside the mask, Uta, ends up possessing him.
- Hak Foo keeps Ikki's mask on for so long that it starts devouring his chi. When it's removed, he's left virtually catatonic.
- Aldarn is convinced he's of strong enough will to control Ikazuki's mask. He's wrong, and Ikazuki quickly possesses him.
- A Possible Encounter for a Phantom: Vlad brought a powerful prehistoric monster called a "Terakon" to life and plans to use the beast to take over the world. Even when it's freed from him and goes on a rampage, Kim calls out how he refuses to see how far this has gone out of his control. To make matters worse for him, the Terakon seems smarter than anyone realizes.
- In Disney's Aladdin: The Return of Jafar, Abis Mal gets pressed into servitude after accidentally summoning the genie Jafar. Jafar accomplishes this by constantly threatening violence against Abis. (The hapless thief is aware that in his world, genies cannot kill, but Jafar keeps repeating ominously, "You'd be surprised what you can live through.") Also, Jafar is the epitome of the Jackass Genie, so it's not like he can make his wishes and be on his way.
- Rasputin of Anastasia was so blinded by his hate for the Romanovs that he really didn't think through his Deal with the Devil. Swearing "not to rest until the last Romanov is dead" unwittingly turns him into a decaying lich because Anya is still alive. Then, when she destroys his Soul Jar, the dark forces immediately intervene to collect on their deal and he dies rather horrifically.
- In the 2009 Astro Boy movie, Stone is very enamored of the explicitly evil Red Core. Experience fails to teach him that you must not play with it.
- In Batman: Mask of the Phantasm, Sal Valestra enlists the Joker's help as a hitman against Batman, whom he thinks is killing off mob bosses. The Joker promptly murders Valestra to use as bait for the hit he himself ordered.
- Batman: Under the Red Hood:
- What kicked off the entire plot was Ra's Al-Ghul hiring The Joker to keep Batman and Robin distracted, believing he could control him. He's proven wrong when Joker goes against his plan by kidnapping Robin and ultimately killing him.
- Black Mask also has some idea of what is going to happen if he releases the Joker, but after the Red Hood fires a rocket launcher at Black Mask, who narrowly survives, the criminal doesn't think he has much of a choice.
Black Mask: I'm being forced into negotiating with a psychotic.
Ms. Li: That doesn't sound good.
Black Mask: No. It's going to be a nightmare.
- In Marvel's Hulk VS animated movie, Loki, in an attempt to defeat Thor, removes Bruce Banner from the Hulk and then uses magic to try and control the Hulk. This doesn't last long as the Hulk's rage soon overcomes Loki's control and the Hulk runs around destroying all of Asgard.
- In The Incredibles, Syndrome sics his own custom-built robot onto a city which he would "save" its people from, all to get back at Mr. Incredible for supposedly slighting him. However, he forgets how intelligent he programmed the robot to be.
- Another Disney example would be The Princess and the Frog. The "Friends on the Other Side" are not at all friendly, as Dr. Facilier realizes way too late in the finale.
- In Scooby-Doo! and the Witch's Ghost, Ben Ravencroft summons the evil spirit of his witch ancestor in hopes of ruling the world together along with her. What he didn't count on was that she was less Evil Overlord and more Omnicidal Maniac.
- The Hellraiser series shows that demonic torturers are never to be trifled with by ambitious summoners:
- In Hellraiser, Frank Cotton releases four demons with the magical cube, which looks quite like some toy. They don't exactly reward him, although it's technically neither a reward nor a punishment. The Cenobites' job is to bring the summoner to the heights of "pain and pleasure", at least in the first film. The summoners never really understand what they're getting into.
- Probably even more true for Hellbound: Hellraiser II where Dr. Channard's obsession with the Lament Configuration ultimately leads to him becoming horrifically tortured and turned into a Cenobite himself. He's horrified at first, but in the end...And to think, I hesitated.
- In Hellraiser: Bloodline, The Duc de l'Isle and Jacques summon a demon princess to suit their whims. She ends up killing both of them, the Duc by seducing Jacques to betray him and disposing of Jacques when he decides to stand in her way centuries later.
- In Mighty Morphin' Power Rangers: The Movie, Ivan Ooze is freed from his prison by Lord Zedd and Rita Repulsa, who hope to get him to join them. Given Ooze utterly hates Zordon, he's perfectly happy to ransack the Command Centre and leave Zordon for dead. However, when Zedd tries to continue treating him like a minion, Ivan traps them in a snowglobe and usurps their base and minions for his own purposes.
- In Turbo: A Power Rangers Movie, the villainess Divatox wants to resurrect the demon Maligore and marry him to gain untold power. When she does, he starts attacking everyone, and is ultimately destroyed by the Rangers.
- In The Mummy Returns, a museum curator, Hafez, deliberately digs up and raises Imhotep, thinking that Imhotep would defeat the Scorpion King. The fact that this would lead to an evil undead ruling the whole world apparently didn't cross the curator's mind. That or it did and Hafez figured Imhotep would let him help rule the world.
- In Fido, the kid takes his pet zombie to the park to play catch. When the collar controlling its zombie nature malfunctions, it eats an old lady and nearly starts a new Zombie Apocalypse. The adults of the movie barely punish him for this.
- In Pirates of the Caribbean: At World's End, both Barbossa and Beckett are convinced they have what it takes to keep evil on a leash and working for them. First, there's Calypso, a vicious pagan goddess bound in human form by pirate lords, who Barbossa — a pirate lord himself — disrespectfully throws in the brig, with the intention of unleashing her on Beckett. Several other pirate lords comment on this, certain she'll immediately smite them in revenge if she gets her powers back. As she reveals to Davy Jones, they're right. The only reason she doesn't is because Will tells her that Davy Jones (her former lover) was the one that taught the pirate lords how to bind her. Instead of smiting anyone, she creates a maelstrom to put two sides she hates at a Mutual Disadvantage.
- Then, there's Davy Jones, Calypso's ex-lover turned heartless Reaper, who Beckett has enslaved and intends to have take on the entire Brethren Court for him. The moment Jones has the chance, he horribly murders Beckett's Dragon. The only reason he doesn't kill Beckett too is that he then loses the fight against the Brethren Court. Had he won, Beckett surely would have been next on his list.
- The Librarian: Curse of the Judas Chalice: A group of former KGB agents, wishing to restore the Soviet Union, try to resurrect Vlad Dracula in order to create an army of invincible undead soldiers. They hope to control the infamous vampire by using the Judas Chalice, but it's revealed that the handicapped vampire-obsessed professor they brought with them was in fact a disguised Dracula, who proceeds to feast on the men and turn them into his vampiric minions.
- In Freddy vs. Jason, Freddy provokes Jason into rising up and attacking the teens of Springwood, in order to stir up a fresh generation's fear and give himself the power that'll let Krueger escape from Hell and continue killing himself. The plan works, but Freddy failed to anticipate that Jason wouldn't stop killing, stealing Freddy's potential victims in the process.
- Dr. Flemming in The Lost Skeleton of Cadavra becomes the titular skeleton's bitch after resurrecting him.
- Dr. Cocteau in Demolition Man brings convicted criminal Simon Phoenix out of cryogenic imprisonment and gives him all sorts of weapons and combat training so he will kill rebel leader Edgar Friendly. Since Phoenix is already an Ax-Crazy terrorist and mass murderer, this ends badly for Dr. Cocteau.
- In the film version of The Wave, a teacher starts a youth movement to make his lessons about autocracies more immersive. While the students initially play along just to humor him, the Wave soon spreads beyond his control. Realizing that he also got into his leader role a bit too much, he summons the class together to call the whole thing off and show what they have become. The class outcast refuses to believe it and whips out a loaded gun.
- The Dark Knight Trilogy:
- Batman Begins: Falcone works with Crane and Ra's al Ghul for the drugs they smuggle, unbeknownst that the latter two are actually aiming toward higher, more destructive goals. In addition, Crane thinks Ra's is holding the city ransom, not planning to destroy it without prompting as the case really is.
- The Dark Knight: The mob finally turns to The Joker to take down their ever-growing nemesis Batman. However, they don't fully understand what drives the Joker.... He ends up burning all of the mob's money and (directly or indirectly) leading to the deaths of the most powerful mob bosses in Gotham. His machinations cripple the mob in a way Batman could have never dreamed of.
- The Dark Knight Rises: Bane is hired by Daggett to commit a robbery on the Stock Exchange and bankrupt Bruce Wayne. As it turns out, Bane was using Daggett all along, with Bane ultimately betraying and killing him.
- In Dracula II: Ascension, a group of idiots (to call them scientists would be charitable, at best) steal Dracula's coffin, hoping to replicate his immortality. Dracula is weak, but very much alive. It's demonstrated, for all to see, that his immortality is magic (holy water burns an infected tissue sample). One character deliberately infects himself, another infects someone else to save him (she, at least, was already infected and had yet to turn).
- In Judge Dredd, Justice Griffin tries to use Rico to instill chaos and thereby reopen the Janus project, intending to clone an army of Judges to enforce order in the city. He doesn't seem to realize until too late (despite the mountain of evidence) that he has literally no way to control Rico, and gets himself ripped apart by a robot for his trouble.
- The plot of Star Trek Into Darkness is kicked off by the fact that Admiral Marcus tried to use a man named John Harrison to make weapons for Starfleet. So, what's the problem here? John Harrison is just a pseudonym. He's really the revived Khan Noonien Singh. This ends just as well as you'd expect.
- Jerry Lundergard in Fargo thinks that he can hire a couple of out-of-town hoodlums to kidnap his wife, extort the ransom from his father-in-law, and have her returned safe and sound. He is tragically wrong.
- Almost all of the Alien franchise is perpetuated by Weyland-Yutani's misguided belief that they can contain a Xenomorph and sell it as a weapon. They never do, and lots of people always die as a result. On the other hand, they never really get the chance to capture and study/sell the Xenomorphs, the (expendable) people directly fighting the Xenomorphs (presumably aware of this trope) always decide to kill them before the company ever actually gets their hands on them. Though from what we've seen, the company would be completely unable to contain them. In Alien: Resurrection the military tries to weaponize the Xenomorphs too, and the personnel on the same ship as the aliens pay for it with their lives. In the Alien Versus Predator films, the Predators deliberately seeded worlds with Xenomorphs to provide them with sport. In both films this backfires on the Predators when the Xenomorphs start hunting them. Of course given the Predators life believes, they'd probably consider this a sign they have in fact found worthy prey.
- Delacourt from Elysium thinks she can keep Agent Kruger on a leash. When he screws up, she starts chastising him for his recklessness. This bites her in the ass. Big time.
- In X-Men: Days of Future Past, Wolverine and Professor X free Magneto from his metal-free prison to get him to stop Mystique. Of course, he develops his own agenda...
- Death Warrant: The prison officials, on the orders of their mastermind, bring the Ax-Crazy killer the Sandman to their prison to kill the undercover cop Burke. The Sandman uses the opportunity to release all the prisoners and start a riot for his own amusement.
- Transformers: Age of Extinction reveals that humans have been using parts of Decepticons (including Megatron) to build their own Transformers. Guess what happens. No go on, guess.
- In Batman v Superman: Dawn of Justice, Lex Luthor turns Zod's corpse into a mutated, unstoppable "deformity" (Doomsday) as his trump card against Superman. As soon as Doomsday is released, the first person he attacks is, naturally, Luthor himself — had Superman not got in the way of the punch, Luthor would have been paste on the wall.
- In Suicide Squad, Amanda Waller thinks she can control Enchantress (an immortal sorceress from another dimension) indefinitely. It backfires, as Enchantress finds a way to escape containment and free her demonic brother, and ends up a world threat. She's actually the first problem Task Force X (the Suicide Squad) is sent to handle.
- Kull the Conqueror: General Taligaro and the dead king's cousin decide to revive an ancient demon witch queen to remove Kull from the throne of Valusia. This of course ends up backfiring when she demotes them both to mere minions and takes over herself.
- Happens more than once in the Godzilla franchise. Creating monsters almost never works in the creator's favor, and neither does blindly trusting genocidal aliens. Doctor Mafune's mad scheme to aid the Black Hole Aliens and control Titanosaurus in Terror of Mechagodzilla ended badly. He ended up being used as a Bulletproof Human Shield, his daughter committed suicide and his Titanosaurus was killed by Godzilla.
- In Destroy All Monsters, the alien Kilaaks attempt to mind control all of Earth's monsters and use them to take over the Earth. Not only does this NOT work, Godzilla goes out of his way to kill them all once he's set free of their control.
- Godzilla: King of the Monsters (2019), Emma Russell and Alan Jonah release King Ghidorah as part of their gambit to heal the Earth by releasing the Titans. Unfortunately for them, it turns out Ghidorah has his own plans and nigh instantly takes over as the film's Big Bad.
- Occurs more than once throughout the Halloween franchise, but given special emphasis in Halloween (2018). Whether it's a cult trying to use him for their own shadowy goals, people attempting to exploit his legend for a reality show or podcast, or people that wish to allow him to roam free to "better understand" him, no attempt at manipulating, exploiting or studying Michael Myers ever ends well.
- In the Super Team parody film Mystery Men, Captain Amazing is so amazing at his job that all the supervillains who threatened Champion City are either dead or in prison, and that's bad for him because the corporate sponsors who make all his cool gadgets are pulling their support. So he decides to free his old archnemesis Casanova Frankenstein from the nuthouse to give himself an opponent and a justification to stay around. Naturally, Frankenstein gets the better of him and now the city is in danger and the only people standing in his way are the not-really-kinda-eponymous team of superzeroes. Heaven help us!
- Quantum of Solace: The main villains, a criminal conspiracy known only as "Quantum", turn out to have the backing of the CIA. Felix Leiter is apparently the only agent in the loop about this who realises that this is a terrible idea, and sure enough the Company proves to be completely incapable of keeping their deniable pawns from going off-script.
- Priest uses this in the climax of its several volume long flashback; a corrupt order of priests have succeeded in opening the Domas Porada, the "can" (and it does rather resemble one) containing the fallen angel Temozerela, believing him to be their savior. Unfortunately, Temozerela isn't too fond of humans... he kills almost the entire order with a single breath (he breathes at them and their heads explode), mocks the leader a bit, and them kills him by making demon faces sprout out all over the leader's body and bite him to death.
- The song "A Dangerous Meeting" from Mercyful Fate's second album "Don't Break The Oath", contains this gem, delivered as only King Diamond can do: OOOOooooooooooooOOOOOOOOOOOOOOH, THEY SHOULD HAVE KNOWN, NOT TO PLAAAAAAAAAAAAAAAAAAaaaaaaaaaaaaAAAAY, WITH THE POWERS OF HEEEEEEEEEEEEEEeeeeeeeeeeeeeEEEEEEEEEEEEELL!
- Regret Game is a rather nasty deconstruction of games about lovecraftian summoning of monsters and demons Gone Horribly Wrong.
- The Ars Goetia includes instructions for making sure that conjured demons don't show up in Eldritch Abomination form, but as something more comprehensible...but given the angels described in the book of Ezekiel, this would apply whether or not they had/have a low opinion of humanity. However, there are four exceptions, besides the pomp-and-sycophantry-loving kings (Beleth, Belial, etc.), who get special instructions.
- Phenex: Don't listen to his song; in fact, interrupt it as soon as possible (the text doesn't say why, but there's an implication that the conjuror risks becoming Phenex's errand boy...at best).
- Valefor: Beware of his temptations to become a robber; he's trying to get you caught and executed.
- Malphas: Yes, he accepts sacrifices happily, but that opens the gate for him to start deceiving you.
- Andras: Follow the binding procedures to the letter, and ignore every temptation he sends at you to do otherwise. Otherwise? He becomes free to KILL you and every single one of your associates. (No surprise that Andras's powers are causing murder and sowing discord.)
- It is a customary rule in all magic-using religions that you do not conjure up something that is more powerful than you are. If you don't have the power to send it away again, things can get ugly very quickly. Another rule is that magic is held by the rules of karma — the more evil the curse is, the more likely the spell will backfire. This led religions to discourage the use of evil spells in the first place.
- Dungeons & Dragons:
- The sourcebook "Elder Evils" features several evils sealed in cans. One of these, Pandorym, is so alien it might as well add another axis to the alignment diagrams. Plus it's angry. Good luck controlling that.
- The Inevitable trying to release Pandorym isn't doing so for its own benefit, though. It just thinks Pandorym got cheated on a contract and is trying to redress that "wrong." The mages who summoned and sealed it in its can get bonus stupid points when you learn why they did so: to blackmail the gods into letting them keep their worshipers enslaved without interfering lest they unseal the can. Guess how the gods responded to that.
- For that matter, trying to summon any being from the Lower Planes without casting spells to protect yourself and/or contain the creature in question is guaranteed to end badly. A reckless demon summoning will result in both the enemies and the party being killed, if not worse.
- In any RPG based on the Cthulhu Mythos, one of the villains will be trying to unleash an Elder God not to end the world, but to harness its power. To date, not one of them has ever succeeded.
- ...Except perhaps the Ashcroft Foundation from CthulhuTech, but given the inspiration for that particular plot point, we probably just don't know how badly that went yet.
- GURPS Cthulhupunk specifically states that those who wish to use the powers of the Mythos for some specific, human-scale goal - getting rich, unseating a government, etc. - are, too put it bluntly, the stupidest kind of cultist: "The powers of the Mythos cannot be controlled with anywhere near this kind of precision."
- The backstory for Warlord villain Avinaar Esmerek looks like one of these, with the heroes finding an ancient temple, obviously recently disturbed, full of prophesies about the awful things that will happen if the being entombed there ever awakens. However, in the final room he is found Killed Off for Real, with a message from the mysterious Avinaar explaining that he unsealed this evil just to have a worthy foe — and it was too weak, anyway. Cue panic.
- More than a few denizens of Warhammer 40,000 have made the stunningly catastrophic mistake of treating Chaos or something devised by the Necrons like this.
- Many a Necron tomb world has been awoken thanks to the following easy-to-follow plan: Adeptus Mechanicus lands on a planet, attempts to worship the dormant Necrons as befitting creations of the Machine God, gets painfully annihilated to the last man. Congratulations, yet another Tomb World is active and looking to purge the galaxy of all life.
- One of the main divides in the Imperial Inquisition are the Puritans and Radicals. Puritans use established rituals to combat the forces of Chaos, Radicals are willing to use more dangerous methods like possessed weapons and daemonhosts to turn Chaos against itself. This of course leaves them open to daemonic possession and corruption themselves, not to mention the Puritans hunting them down as heretics. Although Inquisitors are usually well-informed about the dangers of Chaos, Radicals are often older Inquisitors, who grow ever more desperate to see results in their unwinnable war against Chaos.
- A notable exception is Ax'Senaea the Thrice-Possessed, who was duped into casting a ritual where she would summon a Keeper of Secrets inside her body and then keep it imprisoned by sheer force of will. Bear in mind that Keepers of Secrets are Greater Daemons of the Chaos god(dess) Slaanesh powerful enough to lead world-wrecking armies and specializing in illusions and sweet-talking, so this is a plan stupid even by 40K standards. She went through with it and... it actually worked. Not content with leeching a Greater Daemon dry, she did it again. Twice. On the fourth attempt, Slaanesh hirself showed up and ascended her to immortality as a daemon princess, both as a reward and as a giant middle finger to hir defeated daemons.
- A website referenced a Vampire: The Masquerade game where evil cultists wanted to revive and enslave Caine, the first vampire, while the PCs were to behold the impending doom, their hands carefully tied. Due to a PC heroically tossing his shoe to one of the cultists, the ritual was screwed up: Caine was revived but not enslaved, and the rest of the world was safe(ish).
- This is how one Gehenna scenario ends for the Followers of Set. The clan as a whole descends from an insanely powerful vampire they believe to be the god Set from Egyptian mythology, and worship him by tempting others into wickedness. Well, when he finally wakes from his millennia-long slumber, he can't believe his childer would stoop so low as to worship him, and starts eating them like popcorn.
- The Baali are a bloodline traditionally in service to various cosmic horrors and demons, calling on them for power. The Black Hand: A Guide to the Tal'Mahe'Ra introduces a Baali faction out to stop the rest of their bloodline, along with any other infernalists they come across, before they do something idiotic in dealing with these forces and break the world.
- In GURPS, summoning a demon is temptingly easy to do, even for an inexperienced mage. The probable reason is that demons want to be summoned — by people who can't control them.
- In Magic: The Gathering, demon type creatures tend to be powerful for their cost but occasionally have drawbacks that can screw over their controller unless steps are taken to deal with them. Certain demons like the classic Lord of the Pit and Archdemon of Greed demand regular sacrifices from their summoners and attack them if they are denied. Bloodgift Demon and Griselbrand both have abilities that allow their summoners to trade life for knowledge, and players can easily render themselves vulnerable to an opponent's surprise attack. Abyssal Persecutor will decimate your opponent's forces but it also keeps him/her from losing and you from winning just to keep the slaughter going for a little longer. Rakdos the Defiler is so hard to control that he is just as dangerous to his summoner as he is to the opponent.
- The Dark Eye has the story of mage-emperor Fran-Horas who, in order to put down a particularly troublesome revolt against his rule, summoned the Archdemons themselves and unleashed them onto the battlefield. They proceeded to wipe out the rebels...then turned on Fran's own forces, plunging the realm into chaos. Fran-Horas himself ended up dragged to hell a few years later, having first had to witness the fall of his empire. And a couple of generations down the line his descendant, the empress Hela-Horas tried to do the same thing. Another century or two of Dark Ages was only averted because the gods themselves decided that enough was enough and made a personal appearance to stop the summoning.
- As a core part of Mummy: The Curse, the Arisen pretty much invariably gather cults around themselves, even whilst lying dormant. More than once, a cult has tried to use its patron as a tool, aided by the fact that rising from the grave in an amnesiac state and being bound to fulfill whatever purpose they were called back for is an inherent part of the Curse. However, what these cultists fail to take into account is that the Arisen are amnesiac, not mindless, and they do not simply fall down dead again once their purpose is fulfilled; they get to stick around and do whatever they want for a good while first. And their cultists are quite expendable...
- In 8-Bit Theater, Black Mage tries to control unstoppable forces of evil whenever possible, usually causing a double-subversion or whatever might be hilarious. He takes control of an accidentally summoned Eldritch Abomination—pretty successfully, since it's almost as sociopathic as he is—until one of his "friends" accidentally kills it. He tries to become the ruler of Hell, and he does, but then someone brings him back to life. Played with most destructively in the end: Sarda absorbs Black Mage's super-evilness, which seems to work fine, until he explodes and turns into Chaos. And Black Mage immediately tries to control him.
- Angel Moxie, Tristan helps release Vashi on the promise that when Vashi's boss Yzin takes over the world Tris can rule France. Vashi lied. Tris got mad and punched Vashi so hard she landed in China, before joining the good guys.
- Girl Genius. Zola releases and tries to help The Other. One Gilligan Cut later and she's hog-tied and an unwilling test subject for another fine display of Mad Science.
- A Modest Destiny: The villain Gilbert raises Deo-Deo from the dead, in exchange for immortality. However...
- Vaarsuvius in The Order of the Stick makes a Deal with the Devil and actually does get huge amounts of power temporarily. Having accomplished a couple hits against evil, s/he's now DePowered back to his/her usual self, with the added bonus of putting him/herself in debt, jeopardizing his/her alignment, and making several powerful entities really, really angry. Plus coming back to bite the party in new and interesting ways with the death of the Draketooth clan as well as gods alone know how many other innocents across the Western Continent. Oops.
- And on top of it all, his/her mate filed for divorce.
- Xykon also believes (and this is whole plan) that he will be able to control the Snarl. Instead, he'll just unleash a god-destroying monstrosity that has no idea of control at all. Redcloak knows this full well, and has other plans of his own.
- To say nothing of Redcloak recruiting Xykon to help with his plan to give the Dark One control of a gate and then turning Xykon into a lich when the plan went awry, making Xykon far more powerful and far more evil than before, to the point that he overshadowed Redcloak.
- In Sinfest, a yokel ridicules Satan's stand and sells him his soul. Gets processed, and gets the T-shirt he asked for, and to burn in flames.
- In the "K'Z'K" arc of Sluggy Freelance, Gwynn summons a demon to wreak vengeance on Riff. Unfortunately for Gwynn, the demon goes about this by possessing her, stealing her soul, and warping her body into some sort of monster. Oh, and it turns out that, once the demon fulfills its contract, it's free to destroy the world.
- In Cucumber Quest, the summoned Nightmare Knight reminds Cordelia that he's not her servant.
- Sonic the Comic Online!: In issue 266, Dexter Bagstille captures Sonic, planning to harness Super Sonic to end the war with Robotnik once and for all, using a special Chaos Containment Collar to keep him under control. It initially seems to work... but when the Omni-Viewer and Team Chaotix arrive on the scene, Super immediately attacks Omni and drains his power before going on a rampage, all while mocking Dexter for thinking his plan would work. Once Super is dealt with two issues later, Dexter is put on trial and convicted for his stupidity. Sonic even lampshades how stupid Dexter is to think his plan will work, pointing out that everyone who has tried to control Super Sonic has failed.
- In Hitherby Dragons:
"This is the work of the Fisher-Price Ultimate line," says the talking learn-the-alphabet game.The sky swirls and there is an impression of death and sorrow."In their laboratories they built a childs toy prototype for ultimate evila toddlers first ultimate evil, as it were. The final product would have had safeties, seals, restrictions."Susan sees the direction of this speech."But not," she says, "the prototype?"
- In The Gamer's Alliance, a greedy mage uses an ancient spell in the Second Age to release the imprisoned demon lord Yurius in order to use him for his bid for power over the kingdom. Yurius immediately kills him for his troubles.
- SCP Foundation: Incident 668-682, where a disgruntled agent (subsequently referred to as "the Victim") tries to smuggle a weapon to Omnicidal Maniac SCP-682.
- Red vs. Blue:
- Wyoming's plan in The Blood Gulch Chronicles involves kidnapping Junior (the alien Chosen One and Tucker's kid- it's a long story), letting Omega possess him, and using him to gain control of the aliens by subverting their religion. Which, as Church points out, would end up with a murderous megalomaniac in charge of an army of aliens if it succeeded, probably giving humanity even more problems. Thankfully, the Blood Gulch Crew manage to stop him just in time.
- For most of Revelation, the Meta seems to be treated as a guard dog of sorts by Agent Washington, and manages to somehow be a comedic foil for Wash and Doc. At the end of the series, he captures the AI Tex to return his lost powers, and promptly returns to being the Ax-Crazy Implacable Man he was in Reconstruction.
- In Prolecto, it's subverted big time. Sonya, knowing Azazel was not a toy, took appropriate precautions, and through the majority of the book controls Azazel perfectly.
- In Twig, Reverend Mauer attempts to provoke his enemies into overreacting by creating primordial life (life which can rapidly modify itself) and then publicizing the resulting atrocities. Unfortunately, the primordials don't particularly like being used up and discarded, and so release a final, spiteful curse upon humanity before their destruction.
- Defied by OP in the Elfslayer Chronicles. The DM tosses the Eye of Blight, a sentient magical artifact, in his way, and he promptly buries it and has nothing more to do with it for the rest of the campaign. He's smart enough to know that a sentient evil artifact called the Eye of Blight is something that cannot be good news for anyone, especially the wielder.
- In Ruby Quest, the Metal Glen tries to use a mysterious substance found (along with multiple creepy artifacts like a dummy that rotates on its own so it's always staring at you) in a room buried under the ocean as a cure-all. It did not turn out well. The substance (heavily implied to be the flesh of an Eldritch Abomination) corrupted all who took it, twisting it into the horrific place that it is at the beginning of the quest.
- Part of the shared backstory of Tribe Twelve, Dark Harvest, and Everyman HYBRID is that the Nazis, and later American scientists working with ex-Nazi scientists, attempted to recreate the ancient rite of Gorr'Rylaehotep (a.k.a., Slenderman).
- In No Evil Charles can largely control the Black Tezcatlipoca, as it's somehow chosen him as its' wielder, but he can't awaken those it puts into comas. Amaroq uses this to his advantage by sitting on him, and pointing out he's not strong enough to lift him off, in one episode. And then in "Black, White, and Red All Over" he breaks open the mirror piece of the Black Tezcatlipoca, which was sealing the far more aggressive Red Tezcatlipoca, oops.
- The Adventures of Puss in Boots has Uli spend over three seasons trying to summon an Ancient Evil known as the Bloodwolf. Said Bloodwolf wonders why he should be grateful toward Uli for any of this.
- Aladdin: The Series: In the bulk of his appearances, Abis Mal is shown tracking down various magical beings and artifacts, hoping to use them to conquer Agrabah. Inevitably, the being/artifact in question will turn on him, forcing Aladdin and co. to step in and save the day, but Abis never learns.
- Non-evil version in Avatar: The Last Airbender when an Earth Kingdom general is trying to find a way for Aang to trigger his Avatar State to fight the Fire Nation. He does so by threatening the lives of Sokka and Katara. Aang's Avatar State is activated... and is looking for the one threatening his friends.
- Batman: The Animated Series:
- In the episode "Birds of a Feather", Veronica Vreeland brings The Penguin into her social circle as a publicity stunt. He eventually finds out he's being used, and in his true flamboyantly villainous fashion, kidnaps and attempts to murder her. An especially depressing case as Penguin genuinely had performed a HeelFace Turn and truly was being a good man now... until he learned the truth about Veronica and his heart was so thoroughly broken he dove head-first back into villainy.
- There's also the episode "Joker's Wild," in which a casino owner opens a Joker-themed resort, thinking the supervillain will destroy the place out of spite and bring the owner a hefty insurance check. Once the Joker is wise to the con, though, he instead sets his sights on making sure the owner is part of the total loss.
- And then there's "Mad Love," in which Harley springs the Joker from Arkham, desperately infatuated with him and convinced they'll live out a Bonnie-and-Clyde-esque romance. The feelings aren't exactly mutual, and their relationship quickly turns into a nasty cycle of abuse and betrayal from Joker's end.
- "Over the Edge" has Commissioner Gordon enlisting Bane to help him bring down Batman. Of course, it ends as well as you'd expect a deal with a supervillain to go.
Gordon: We had a deal!
Bane: Thought about it. Didn't work for me.
- In Ben 10: Ultimate Alien, Vilgax messes with Diagon's seal in an attempt to claim the demon's power and is promptly mutated and enslaved by it. The "Evil" eventually turns out to be Vilgax.
- One episode of Captain N: The Game Master centers around Mother Brain's quest to free Ganon (the Big Bad of The Legend of Zelda), so he could help her conquer Videoland. Unfortunately for her, she seriously underestimated his douchebaggery. As Ganon puts it, the only being Ganon serves is Ganon.
- In the five-part Centurions episode "Man or Machine", Mad Scientist Doc Terror recreates an alien Master Computer on Earth because they share the same goal—ridding the world of organic lifeforms. Terror assumes that as a cyborg, he'll be spared. He's wrong.
- Codename: Kids Next Door: In "Operation: Z.E.R.O.," Father acquires the Recommissioning Module and uses it to reawaken Grandfather, the "world's most ultimate evil" in his words, and his actual father. Almost immediately upon being reawakened, Grandfather thanks Father for doing so... and then harshly dismisses him, pointing out that the only reason he needed to be brought back is because Father and the other villains weren't able to stop the Kids Next Door themselves.
- In Danny Phantom: Vlad Plasmius attempts to gain enormous power by stealing the Crown of Fire (having already obtained the Ring of Rage). He opens the sarcophagus of Pariah Dark, waking him up. Within minutes, Vlad is beaten, and is forced to team up with Danny to stop him. He falls into the same trap with Vortex after his Restraining Bolt is accidentally destroyed.
- Darkwing Duck:
- F.O.W.L. decides to find Taurus Bullba (the villain from the pilot and one of the only non-goofy villain of the series) and rebuild him as a cyborg. He was pissed. His voice is dripping with bitter sarcasm when he says, "So what if I have to drink motor-oil cocktails for the rest of my LIFE?"
- In the comics, F.O.W.L. high command decided to revive Duckthulu. Surprisingly, Duckthulu thanked them by disposing of them and then continuing to destroy all of reality.
- Dexter's Laboratory: A rare subversion occurred in one episode, "Jeepers, Creepers, Where is Peepers?", where GOOD is not a toy. An evil alien warlord kidnaps DeeDee's first imaginary friend, Peepers, a cute yet obnoxious furry critter who rules over her imaginary world of Koosland, to use as a potential energy source for his secret weapon. After being battered around by Dexter and DeeDee's other imaginary friend, Koosy, the villain's taunting is cut short as he realizes in an Oh, Crap! moment that he is about to be smushed into a pancake by Peepers, who has mutated (not transformed, but mutated) himself into a flesh-coloured, evil-looking dragon (who also makes his own evil-sounding laugh afterward).
- In the DuckTales (2017) episode "Mystery at McDuck Manor!", it looks like this has happened when Black Arts Beagle summons what he believes to be a demon, only for him to disappear literally shouting, "I'm not as good as I thought I was!" As it turns out, he's summoned the ghost of Scrooge's old butler, who was sort of behind everything anyway and later admits he has a flair for the dramatic.
- In "Computron Lives", an episode of The Galaxy Trio, a group of would-be terrorists find the deactivated Computron, the first villain of the series, and decide to wake him up so they can use his power to conquer the world. They survive the experience, but really ought to have known better, given that his defining qualities had been his self-determination and contempt for organic life.
- Gravity Falls:
- Played straight in "Dreamscaperers" where Gideon, trying once more to get a hold of the Mystery Shack, summons a certain triangle shaped Dream Demon to help steal the deed to the Shack. Bill Cipher goes on to become the Big Bad of the series, eventually coercing Gideon into being Demoted to Dragon when Bill finally breaks the barriers between his world and reality.
- Averted by Dipper in "Northwest Mansion Mystery". While he is angry at the Northwests for taking advantage of his willingness to get rid of the ghost and sympathizes with the ghost's desire for revenge, he recognizes that the ghost is unstable and doesn't want to risk letting him out of the mirror he sealed him in while his sister is at the party. Unfortunately, the ghost averts Evil Cannot Comprehend Good and appeals to Dipper's better nature by asking him to hold the mirror up so he can see the trees one last time before he is exorcised. When Dipper agrees, the ghost heats the mirror up, causing Dipper to drop and break it.
- He-Man and the Masters of the Universe (1983)
- An episode had an evil sorcerer freeing an evil dragon, and said dragon sticking the sorcerer into his old prison.
- In "To Save Skeletor", Skeletor decides to summon an elder god. You can guess from the episode title how that worked out.
- Jackie Chan Adventures has the main antagonist, Shendu the Fire Demon, constantly betraying any allies he works with, especially if they're human villains attempting to free him from whatever fate he's trapped in.
- In Season 1, Shendu, who was turned into a statue for almost a millennium, promises to reward the Dark Hand (Valmont and his Enforcers) with vast ancient treasures if they acquire all the magical Talismans needed to release him. Upon Shendu returning to his true form, he completely reneges on their deal and refuses to pay up.
- In the Season 3 finale, Shendu (now a spirit) pulls this on Daolon Wong, who offered to resurrect him in exchange for giving Wong the Dragon Talisman power that Shendu's body will attract. To the surprise of absolutely no-one (except for Wong of course), Shendu takes both the Dragon power and the other two Talisman powers (Pig and Rooster) that Wong had acquired earlier.
- Justice League:
- Felix Faust releasing Hades. He learned from his experiences, and was able to live out the more fun side of the trope by possessing Tala later on.
- And with Dr. Milo releasing Doomsday.
Milo: And you'll solve both our problems?Doomsday: Yes. Release me.Milo (deactivating the restraints): ...Wait! What are you doing?Doomsday (seizing Milo by the head): Your problem's solved.
- A bunch of teenagers tried to do some cult like ritual hoping it would grant them powers; it goes awry and instead summons Solomon Grundy back from the dead. His first victim was one of the teens.
- Invoked in the finale of the show: Lex Luthor attempts to revive Brainiac from his last known gravesite so he can team up with him again. To do this, he uses the Evil Sorceress Tala as a conduit to revive him, a process which will kill her. Unfortunately for Lex, said area was also the gravesite of Physical God and Galactic Conqueror Darkseid, and you get no points for guessing which one of the two Tala ends up reviving as a final 'gift' to the man who killed her.
- Averted in The Legend of Korra. Despite being the personification of chaos and darkness and having a great hatred for humans, Vaatu's arrangement with Unalaq is entirely on the level. He could've betrayed Unalaq during their Fusion Dance and still achieve the result he wanted, but presumably, their mutually beneficial goals kept them on the same page.
- In the Looney Tunes cartoon "Dr. Devil and Mr. Hare", Bugs Bunny creates a robotic Frankenstein's Monster-esque creature to protect him from the Tasmanian Devil. The monster beats up Taz, then beats up Bugs right after.
- The Mummy: The Animated Series: In the pilot episode, Colin Weasler uses the Book of the Dead to resurrect Imhotep, believing that he could use the book to control the mummy. Unsurprisingly, Imhotep promptly takes the book back, forcing Weasler to become his Evil Minion in exchange for his life.
- In My Little Pony: Friendship Is Magic: Celestia decided to release Discord, a Laughably Evil Mad God, so she could put his Reality Warper powers to productive use. Even her most faithful student thinks she's crazy for seriously considering this and even more so for thinking he could be redeemed beforehand. Fluttershy succeeds by befriending him.
- Discord himself has to learn this lesson in the Season 4 finale. Celestia has asked him to stop Tirek's rampage; instead the latter manages to appeal to his vanity and convince him that he is now his new special friend and they should rule Equestria together. As soon as Tirek has grown strong enough absorbing the magic of enough ponies, he promptly turns around and steals Discord's powers as well.
- Trixie tracks down the Alicorn Amulet after the Ursa Incident ruined her life to get revenge...except the Amulet is actually an Artifact of Doom that corrupts it's user and drives them insane.
- In The 13 Ghosts of Scooby-Doo episode "Ship of Ghouls", the ghost captain of the Queen Myrtle plans to free the ghosts imprisoned from the Chest of Demons once his ship has passed the Bermuda Triangle. His attempts to get the released gestalt form of the ghosts to join him, however, result in the gestalt being turning on him and consuming him alongside the other ghosts aboard the ship.
- In Scooby-Doo! Mystery Incorporated, Professor Pericles spent the entire series and a good chunk of his backstory trying to free the entity in the sarcophagus that drove most of the plot hoping to claim its power. In the end, he finally does, only for said entity to use Pericles as a physical vessel, killing him in the process.
- The Simpsons: The Treehouse of Horror segment "Dial 'Z' for Zombies" features Bart using a magic book to resurrect the family cat Snowball. It worked... except it didn't revive the cat, but rather actual zombies that terrorize Springfield. Bart himself lampshades on the situation he inadvertently started:
Bart: I thought dabbling in the dark arts would be good for a chuckle. How wrong I was.
- In Star vs. the Forces of Evil, Moon Butterfly and the Magic High Commission secretly back Mina Loveberry's conspiracy to overthrow Eclipsa but the utterly insane Mina and her army of Solarian Warriors quickly go out of control, and neither Moon or the Commission can do anything to stop them from ravaging Mewni.
- In Teen Titans, Slade cuts a deal with the demonic Trigon to come Back from the Dead in return for Slade helping the demon take over the world. After Slade fulfills his role, Trigon turns on him. Slade knew this was going to happen and took precautions. He ends up orchestrating Trigon's downfall and getting his mortal life back, and is still at large at the end of the series while Trigon was either destroyed or re-sealed in Hell. Technically, they were sealed in the same can — Trigon was in Hell because he was a demon, and Slade was there because he was evil and dead. However, Trigon seems to have drawn Slade's soul to him, and he was the one who instigated the deal. Slade took it because it was the only chance he had.
- Shredder from the Teenage Mutant Ninja Turtles (1987) series has problems with this. In the pilot, he teams up with the brain from Dimension X Krang, but refuses to create a new body for him because of this trope, but caves in later on. Once the bad guys and the Technodrome end up in Dimension X, Krang takes charge. This pops up later on in Turtles Forever, when Shredder rescues his counterpart from the 2003 series from imprisonment on an asteroid for the purpose of a Villain Team-Up. Unfortunately, the Darker and Edgier Shredder not only takes control of the Technodrome and Krang's technology, but also decides to wipe out creation himself.
- Teenage Mutant Ninja Turtles (2012): In the Season 5 premiere, Tiger Claw summons the Demodragon Kavaxas, intending to use his power to resurrect the Shredder, who Leo killed in the Season 4 finale, using the Seal of the Ancients, a magical talisman that forces Kavaxas to obey whoever possesses it without question, to keep him in line. Three episodes later, in "End Times," Shredder is successfully resurrected, but he Came Back Wrong as Kavaxas' zombie slave and destroys the Seal of the Ancients, after which it's revealed that Kavaxas was just using Tiger Claw to complete the three tasks he needed to accomplish on Earth in order to bring about The End of the World as We Know It; to slay a strong warrior (Tatsu), to resurrect an evil warrior (Shredder), and to destroy the Seal of the Ancients.
- In Transformers: Prime, Megatron tries to revive Unicron so he can rule by his side. When Unicron wakes up he tells him he was wrong about two things: 1) Unicron woke up himself without Megatron's help, and 2) Unicron wants to destroy the universe and everything in it, including the Decepticons.
- This bites Megatron in the ass again in the series finale. Megatron spent the entire series feeding himself with Dark Energon to making himself stronger and create better weapons. Dark Energon comes from Unicron, and when Megatron dies, he ends up being used as Unicron's possessed slave. Unicron makes it abundantly clear Megatron controls nothing and is simply his new puppet and chew toy.
- Xiaolin Showdown. The spirit of a nigh-omnipotent sorceress who was freed from her puzzle-box prison by Jack in the pilot, and promised him the world if he helped her. Although Jack never quite succeeded and eventually became her adversary, when Raimundo restores her powers with his FaceHeel Turn, she repays him by... granting his every wish and grooming him to rule the world alongside her. It seems she was a villainess of her word after all.
- A straighter example is Hannibal Bean corrupting Chase Young. He gives him the Lao Mang Long Soup to turn the monk evil. Once he does, Chase Young betrays him and locks him away in Ying Yang World.