Gaara of Naruto was originally a sad, lonely boy who simply wanted a friend. But the villagers feared his power, and hated him because of its source. Finally, after Yashimaru tried to kill him, on orders of Gaara's father no less, Gaara becomes exactly what Yashimaru and the villagers had always said he was: A monster that loved only itself. Fortunately Defeat Means Friendship, and after fighting Naruto and losing Gaara eventually regains his sanity and learns to trust and love other people again. He later even becomes the new Kazekage, and is now revered by the villagers as a hero.
This may be part of Madara Uchiha's motivation for his Face-Heel Turn after having co-founded the Hidden Leaf Village with Hashirama Senju. Tobirama constantly made moves to limit the power of Madara and the Uchiha clan, which convinced Madara that the old hatreds wouldn't die out. After reviewing the legend of the Juubi, Madara decided to follow a different route to peace.
And later, the Uchiha clan as a whole followed in his footsteps. After the Nine-Tailed Fox attacked Konoha, the village leaders concluded that the Uchiha had to be responsible (as the Sharingan can influence Tailed Beasts).note An Uchiha was responsible...but one that everyone, including his clan, believed to have been long since dead. While outwardly the clan still seemed to still have a position of influence and power, they were being marginalized behind the scenes and feared being driven out of the village. They decided in response to seize power in a coup, something that had been feared by some (such as the Second Hokage) since the day the village had been founded. This...did not end well for the Uchiha clan.
Played with by Lelouch of Code Geass, especially towards the end after things go south for him. He says this after the death of Euphemia.
His mindset when he begins his scheming. He is willing to commit evil if it means taking out greater evil in so doing, or when pushed past the brink. Ultimately, after the Black Knights betray him on suspicion of using them for sport, he loses all restraints and allows himself to become the most despised person in the world...so that the world would focus all their hatred on him...so that his death would remove that hatred and provide a chance for the world to rebuild more positively. One of the best ways to unite the world, he figures, is to give them a common enemy to kill, and since by this point he feels he has lost his reasons to live...
Lilu in Watashi No Messiah Sama. It's made a bit worse by the fact that she was in fact originally supposed to be the Priestess of Salvation but because of a wish Haruna made, she had the position stolen from her and forced into the role of Priestess of Domination. Said wish was made by her best friend, the original Priestess of Domination, and forced her into a life of horrible treatment at the end of which she just snapped.
During the climax of Devilman Lady, Asuka has transformed into a godlike being, brainwashing most of the world into loving her. Meanwhile, protagonist Jun has been cast into a giant (possibly metaphorical) pit, but she manages to rally her strength and declares that if Asuka is "God," then Jun will become the Devil to destroy her!
Rave Master gets hit with this two to three times. The first Big Bad, King, is a questionable case. He starts off more as a Well-Intentioned Extremist before the government rather harshly puts a stop to him, spurring him to go into full on terrorism. Lucia and Doryu make for much clearer cases. Despite being a demon lord, Doryu came to the human world hoping to create a place where all species could live in harmony. When Fantastic Racism became too severe and he was locked away by the people he sought to help, he lost it. Lucia had a similar fate. Coming from a family with a history of villainy, the Empire decided to get it over with and preemptively arrest him. When he was six. That he went to prison because he was expected to become a villain is, ultimately, his motive for becoming a villain.
Wu Fei: I need to determine for myself whether or not peace at the expense of lives can really be defined as peace! And I will become evil itself to find out!
The mid-quel manga add a bit more information to this; in Battlefield of Pacifists Wu Fei befriends an OZ soldier who believes that war drives humanity to new heights, and his personal goal is to encourage deep space exploration by setting a Mecha-Mook factory in the outer solar system. When said soldier is killed, Wu Fei promises to become "the threat that makes humanity grow".
In Higurashi: When They Cry, Shion does this to herself. During her Roaring Rampage of Revenge in Meakashi-hen, she kills Satoko only to remember a promise she made to Satoshi to protect her. She immediately decides that since she's lost any chance of happiness, she may as well become a demon.
Princess Tutu: When her Kraehe persona resurfaces, Rue initially fights back, struggling to maintain her identity as a human being. However, Fakir continually fights her and treats her as a villain, until she finally snaps and lets the Crow Princess take over.
"That's right. I am a crow."
This is a major reason people judged to be "latent criminals" in Psycho Pass because actual criminals. The culprit in the first episode specifically mentions that since he was scanned with a high enough Psycho Pass, his life is basically ruined at this point, so he might as well beat and rape his hostage.
Loki from The Mighty Thor fits, Depending on the Writer. It's almost always more that Loki THOUGHT that the Asgardians didn't trust him and that he was The Unfavorite compared to Thor (combined in some continuities with the reveal that he's a Frost Giant, an Always Chaotic Evil race) that caused his Start of Darkness, not that he was actually disliked/hated. Thor, years later after fighting as the hero to his villain, still cares enough about him to get him reincarnated after Loki engineered the near fall of Asgard and helped save it in a last-ditch Heroic Sacrifice. Enemy Mine has been a recurring thing for Loki when the threat gets too great for a long, long time.
Also, there might have been a bit of Because Destiny Says So, since according to some writers the Ragnarok cycle, while it existed, contained the prophecies of the Norns that wrote the fates of the Asgardians and those around them. Loki might have been dealing with the knowledge that it said he'd be evil.
The seriousness with which the mythological factors are treated in the Mighty Thor materials varies a lot, but it's always going to be...off when it comes to Thor-and-Loki because it requires them to be a set of good and evil brothers, which is categorically wrong in every particular way. Although Thor does seem to have been considered the safest of the Aesir to petition.
Magneto has generally been written as a Well-Intentioned Extremist for a few decades now, which makes the name of his old supervillain group, the Brotherhood of Evil Mutants, seem a little strange. It has, therefore, been stated that the name invokes this trope. If humans are going to be afraid of mutants, he's going to give them something to be afraid of.
Marv wonders if he is unknowingly following this trope in both the film and comic version of Sin City. All his life, people told him that he would grow up to be "a psycho killer" and he contemplates whether or not it's happening.
In the Mexican comic Memin (about a poor Black boy) a story had some bullies convince him that Black people never go to Heaven, no matter how good they are (claiming that the fact there are no pictures of Black angels proves it). Memin is so angry that he swears that if he's going to Hell, he'll rule it by being the most evil kid in the world! (being a preteen his idea of evil acts are things like disrespecting his mother.) His friends hatch a plan to reform him by painting one of the angels in a Church (with the clergy's permission) Black and then show it to him. It worked.
During a visit to Hell, Bane of the Secret Six discovered that despite being a Noble Demon (at least what he thought was one) he was still damned. He figures that since he's beyond redemption anyway, he might as well stop trying to be a half-assed antihero and embraces villainy. First order of business? Settle the score with Batman once and for all.
While it never actually happens, Spider-Man comics have repeatedly teased the reader with the possiblity of Spider-Man becoming a menace due to the All of the Other Reindeer mentality of the world around him. In the Ultimate Spiderman comics, Nick Fury was particularly worried that all of the tragedy and bad publicity in Peter's life would drive him to villainy — and given the combination of Peter's intelligence, determination, and superpowers, that would be a very bad thing.
The Schorcher, a Spider-Man foe, reportedly started out like this. According to his origin story, research scientist Steven Jamal Hudak was framed for embezzlement by a co-worker and had to go into hiding to avoid his arrest. Being a wanted man with little chance of finding work at his chosen field, Hudak used his scientific knowledge to build a Powered Armor and started a career as a freelance mercenary.
Cyclops, after the events of "Avengers vs. X-Men". At first it seemed that he would surrender and stand trial for the murder of Charles Xavier, but after spending some time in prison, he decides that he's more useful outside bars, and since he and his "Phoenix Five" team are already fugitives believed to be guilty, why not take advantage of that to go were the regular X-Men can't go, operate outside the law.
A fair share of Naruto fanfics had him becoming evil because of this trope.
Death Note Equestria: This is invoked by Twilight at the end of Season 2. Realizing that by this point, Kira will never be viewed as the shining beacon of justice Twilight was originally aiming for, Twilight decides to build up the image of Kira as an almost mythical epitome of evil, a monster who targets other evil-doers, in order to scare anyone out of ever breaking the law ever again. Coincidentally, this coincides with Twilight's slip into full-on A God Am I territory.
Also a Shout-Out to The Bible, to which the movie in general sticks pretty closely: the book of Exodus states somewhere around the sixth plague that "Pharaoh's heart was hardened," causing him to stick to his guns and let the plagues continue.
The Creature from the Black Lagoon is given this treatment in the sequel Revenge of the Creature. A science team is sent to Black Lagoon to capture the Creature and bring him back for scientific study. Said "scientific study" seems to mainly involve whacking him with underwater cattle prods for reasons which are never explained. After watching the Creature be harassed and brutalized for no apparent reason in the first half of the movie, a modern viewer may have mixed feelings upon the Creature's escape, where he does, in fact, kill people, but at this point "man, Humans Are the Real Monsters" seems to be an appropriate response.
Repo! The Genetic Opera has a song devoted to this, 'Let The Monster Rise'. It shows how Nathan allows his Repo Man persona take over in order to save his daughter.
Then, even without anyone knowing about his Tomato in the Mirror moment, 7) all his friends reject him as the legal substitute king and go to illegally fetch exiled Thor to replace him, and 8) the most loyal vassal of Asgard betrays him; then 9) when he freaks out about this and sends a giant robot to communicate his rage very poorly, Thor assumes this is an attempt to kill him. So he does.
After this he is basically a nervous wreck but manages to get his plan to save Odin from a danger he created to work, and his mom hugs him, which was basically the goal of his whole scheme. Then 10) Thor reappears and she promptly forgets Loki exists. Finally 11) when after attempting genocide against his own race to prove his loyalty he begs Odin to accept him, Odin says no.
The eponymous Outcast of Redwall has elements of this. A foundling infant from one of the Always Chaotic Evil vermin races (specifically, a ferret) is raised in the Abbey and grows to be quite the troublemaker as a child. Even so, he is treated with little more than suspicion and prejudice by most of the local populace, and rarely, if ever, given the benefit of the doubt, even for his motivations (backfired attempts to do good are still punished without consideration). Ultimately, the message boils down to him still being responsible for making his own immoral choices; but he at least got more sympathy than any other vermin character when one considers what a slim "chance" the Redwallers ever gave him. His surrogate mother never gave up on him and her life is saved by his Heroic Sacrifice.
Huckleberry Finn, sick of being treated as a "wicked" boy who will never amount to anything, eventually declares "All right, I'll go to hell!" and "take[s] up wickedness" by... helping a man escape from slavery. He faces the moral quandary of being 'good' or keeping faith with Jim, and finds himself unable to countenance the former if it is exclusive of the latter. He believes he's 'bad' because he's defying the rules and will be punished, because he's coping with higher morality on an emotional level but completely lacks the vocabulary to deal with it mentally.
Frankenstein abandoned his newly-made monster in disgust at its uncanny looks, and everyone else who ever saw the monster reacted with horror. Is it any wonder the "daemon" became Ax-Crazy?
He became marvelously eloquent first, though. Just from overhearing someone read aloud. Nineteenth century writers believed books could do anything.
It didn't hurt that the family was also teaching a runaway Arabian noblewoman English, and the monster (who was just born, after all) was listening. No, really.
C.S. Lewis uses this in a speech given by Senior Tempter Screwtape in an epilogue to The Screwtape Letters. Screwtape comments that one of the results of the "You're no better than me" school of thought will be to turn anyone even remotely different from the mass public against them. If I will be called a fascist or a monster, I may as well be hanged for a ram as for a lamb, and become one in reality.
The titular Space Brat, Blork, from Bruce Coville's series. He was labeled by the computer nanny as a brat soon after hatching from his egg, all due to his having a piece of shell stuck behind his antenna and crying in pain because of it. Since then, he was the boy who cried wolf, and constantly marked as an easy person to stick the blame on. After putting up with it for a while, he winds up throwing a temper tantrum at how unfair it all was, which was unheard offor his species. Which then gives him a very easy out for whenever he gets blamed for something from then on, leading to this trope.
While it's hardly the only factor, this is one of the main reasons why Jaime Lannister in A Song of Ice and Fire became the cynical and amoral monster he is at the start of the series: The entire kingdom looked down on him for breaking his oath and killing the Mad King Aerys, giving him the mocking name of Kingslayer and an undeserved reputation as a scheming, treacherous backstabber- even though Aerys was about to have all of King's Landing (the capital city, with a population of about 500,000 people) burned down out of spite. After years of being called a monster for what he rightly considers his "finest act," it's not hard to see why he eventually became one, although what fans sometimes seem to forget is that no-one knew what Aerys was about to do and Jaime never bothered to tell anyone (Maybe they wouldn't have believed him, or discounted it, but he could have tried - his father could also have used influence to spread the true story and temper the hatred, had he known). It also happened at the same time as his father sacking the city after the war had in effect already been won at the Trident, making it look like a patently obvious attempt to get on the good side of the rebels and a pointless betrayal; another theory suggests that despite being it a good act, Jaime must have felt deep down he deserved the scorn for the betrayal regardless, or he'd have attempted to defend himself at least (possibly because he felt guilty for having stood by for plenty of Aerys' other horribly insane and cruel acts). Recently, it seems like he might finally be turning his life back around, eschewing his family's toxic influence and taking a newfound pride in his honor as a knight.
Jaime's younger brother Tyrion seems to be heading down this road too.
Sandor "the Hound" Clegane probably qualifies as well.
As the famous line from Paradise Lost goes: "Better to reign in Hell, than serve in Heaven."
"Michael" from Stargate Atlantis was a Wraith who the protagonists forcibly converted into an amnesiac human. His introductory episode has the characters mistreating him for no clear reason (mainly by Ronan, who utterly despises all Wraith due to their wiping out his planet and putting him through years of torture), before he realizes that he's a Tomato in the Mirror and breaks out to return to his people... but they won't accept him either, since he's still partly human. He desperately returns to the protagonists and offers valuable aid, just begging them that they don't brainwash him again. They brainwash him again. When he recovers again, he's fed up of saying What the Hell, Hero?, and he snaps completely and becomes an Evilutionary Biologist.
The fact that Michael has to eat people to survive, and the virus that can transform a Wraith into a human (thus removing the need to kill people to keep him alive) inherently causes amnesia, explains why they felt the need to brainwash him, though.
Adam Wilson from The Young and the Restless has ended up invoking this trope. It's hard to escape the fact that, before he came to Genoa City, Adam was relatively moral and well-adjusted. It was only after prolonged exposure to the chronic backstabbing and underhanded business dealings of the city that he started his horrific revenge plan — and at the end of that, he lapses into a My God, What Have I Done? moment and tries to reform. Then even this is completely undercut when the Newmans and Abbotts confront him in the cabin and treat him like a monster, even though they don't have any idea what he did — plus how hollow their moral superiority sounds, considering all the crimes they've committed in the past, which Adam and later DA Owen Pomerantz call them out on.
When Ashur of Spartacus: Blood and Sand gets berated at for his slimy Manipulative Bastard behaviour, he pulls this line of defense, pointing out that everybody treated him like pig feed and that nearly every git move he pulled benefited his master, doctore, and the ludus, so screw the gladiators and their honour.
Star Trek: Deep Space Nine featured an episode in the second-to-last season where Gul Dukat tries to convince Sisko (and himself) that they really were friends all along and that he has always been misunderstood as merely an Anti-Hero, not a true villain. Eventually, with some subtle goading from Sisko to drop his facade, Dukat realizes that he has always been a villain and decides to embrace his role by destroying Bajor and everything Sisko cares about.
A variation also occurs in the episode where Sisko goes after the traitor Eddington. He realizes that Eddington sees himself as a hero fighting for a noble cause and decides that he has to embrace his role as the villain in Eddington's mind in order to beat him. He eventually engineers a situation that plays to Eddington's nobler instincts, forcing him to turn himself in to stop Sisko's villainy.
To be clear, his villainy consisted of poisoning a Maquis planet in such a way that humans couldn't live there (but Cardassians could), essentially just balancing out the nearby world Eddington had just poisoned to Cardassians but not humans, and then threatening to do so to every Maquis settlement he could find.
Winn Adami concerns herself less with the spiritual and more with political. She ends up Kai (the head of the Bajoran religion) but still doesn't give up the power game. After Dukat, with the help of the Pah-wraith, manages to seduce her, she stops receiving visions from the Prophets. Realizing they have rejected her for consorting with their enemy, she chooses to join the Pah-wraith out of spite.
A major theme in Smallville. Lex Luthor makes several efforts to do good and often helps Clark and others save the world, but several characters- especially Clark's parents, no less- treat him with suspicion at best because he is the son of local Corrupt Corporate Executive Lionel Luthor, who himself had been trying to mold his son into another ruthless Magnificent Bastard (whilst simultaneously letting Lex know just how much of a disappointment he was). The latter stuff really had put the seed of evil in Lex's heart- Oliver Queen knew Lex at school and saw him beat up his best friend (though Oliver had been a bit of a dick to both of them, mind), and a horrified Lionel covered up the fact that as a boy Lex had murdered his own baby brother though it turned out, Lex only took the fall for his mom, who wanted to spare the child Lex's horrible childhood. There is a lot of tension between Lex's natural bad side and his desire to genuinely do good getting screwed over; he is particularly annoyed that Clark, his best (and only) friend, is obviously hiding stuff from him- Clark, for his part, has thought about revealing his secret to Lex but has been dissuaded by, amongst other things, hallucinations, that make it seem like a bad idea. Not helped by the fact that the two of them are aware of a prophecy about a mortal man fighting a godlike alien and Lex believing that to Beware the Superman might actually be sensible; after all, how can anyone be trusted with that much power?
Several episodes are devoted to Lex's own internal struggle. One such story inverts A Christmas Carol- Lex, having been shot at Christmas, meets the ghost of his mother who shows him what happens if he changes his ways: he has a loving and happy marriage with Lana and is finally treated like a friend and family member by the Kents; Clark holds no grudge about the two of them marrying either and is happy for them and remains his best friend. Then Lana gets seriously ill and Lex can't afford it, so he goes back to his dad to ask him to help...and is promptly brushed off, meaning Lana (and their baby) both die because Lex gave up his money and his wicked father's fortune. When he wakes up, Lex decides that money and power are the only things that really matter in life, because then you can protect the people you love.
Lionel himself gets some of this. Early in season 4 he is in prison, and tries to escape by swapping bodies with Clark, naturally discovering his secret in the process. His plan fails and he ends up back in his own body by the end of the episode, but afterwards professes that he is a changed man (and faking amnesia about finding out Clark has powers and the whole body-swap thing) and after getting out of prison on a technicality anyway, tried to convince the rest of the suspicious cast, meeting the most resistance from Lex himself, who is also trying to earn everybody's trust. Things hit a head in one episode when Black Kryptonite splits Lex into his good and evil halves- the good Lex lets his father know he'll trust him and encourages him in his do-goodiness; the bad Lex goads Lionel into assaulting him with a poker, then says that proves he hasn't changed at all. Turns out Lionel really had changed, but by the end of that episode, and never finding out about the whole split-in-two thing, he tells the now whole Lex that he was right- "we're Luthors", and they should embrace the Card-Carrying Villain within, though to his credit Lionel is never quite as evil again and never exposes Clark's secret, generally deciding he'll help him from now on.
Eventually Good!Lionel becomes Clark's new father figure, and does all the things for Clark he never did for Lex, leaving by-now-lost-to-the-Dark-Side Lex justifiably frothing at the mouth at the unfairness of the universe.
Buffy the Vampire Slayer. Spike tries to enlist in the good fight after falling in love with Buffy, who regards this Heel-Face Turn with suspicion, especially after discovering his true motive. However he gains some trust by protecting Dawn in Season 5 and acting as her confidante in Season 6, but when Buffy realizes she's falling for Spike she starts physically and verbally abusing him in order to drive Spike away. As Buffy refuses to let him be good, he decides the only way to get Buffy is to drag her down to his level, leading to their Destructive Romance. Though he was a monster for at least 100 years prior to getting the chip and falling in love.
Eventually subverted, as Spike arranges to have his human soul restored and becomes a hero for real. Though not a nice one.
In The City Hunter, LeeJin-Pyo's sole purpose is to find and punish five corrrupt and murderous politicians; not an unworthy cause in itself, although he knows from the beginning that his method of revenge—kidnapping his best friend's infant son and raising him as an instrument of vengeance—is unforgivable. But since that's what he started, he's damned well going to finish it.
One arc on Desperate Housewives had Lynette trying to stir concern about the fact that there was a possible pedophile living with his sister on Wisteria Lane. However, the attempts to stir up hysteria drove the sister to suffer a fatal heart attack, at which point the guy told Lynette he'd kept his urges under control because of her. And now he was going to leave Wisteria, and had no reason to curb his impulses... and he wanted her to know it was all because of her (however, since it was never really confirmed that he really was a pedophile, it is possible he's just messing with her head).
This is the ending of Tripod's song "Suicide Bomber"—the falsely accused bomber is awaiting release after repeated torture, and is already planning to blow up a bus.
Happens in Adam Warrock's song, "Sad Ultron"— All the newest incarnation of Hank Pym's Ultron wants is to hang out and be accepted, but because all previous versions of him went all Knight Templar and evil, everyone assumes he'll do the same- thanks to being shunned and hated, he turns evil on principle.
"Sorry y'all, I tried to be a nice dude, fuckin' human intelligence made me wanna fight too/And that's ironic, isn't it? The fact that human indifference made a robot turn evil and villainous/Fuck it, I'm engaging a plan to kill Hank Pym/ Ask me if I'm one of those nice robots, I'm not him."
They say you are a lady of vice and disdain, then I am evil as well, with the same blood in my veins.
It is not uncommon for Storytellers to use this tactic in Hunter The Reckoning. Since almost all of the mook monsters you meet actually have a measure of humanity and are enslaved to their natures or other, worse monsters, there is already a bit of a gray area to killing them in the first place. Since hunters constantly hound the monsters, cutting off their resources and food supplies, they can eventually get fed up or be driven to desperate acts of violence since their beastly side starts taking over. This could cause a normally nice vampire who only drinks just enough blood to survive, and only from animals, to become a raging beast draining the nearest humans dry. If the monster survives, you can bet he won't care much about keeping his humanity anymore. Expect angry party members who have more forgiving views of the monsters.
In the New World of Darkness there's the Refinement of Stannum in Promethean: The Created, which is centered around wrath and getting revenge on the world that scorns you at every turn. Prometheans eventually draw the wrath of humanity and the suffering of nature everywhere they go, and Stannum is about focusing that wrath where it belongs. Each Refinement is a philosophy the Promethean follows during their Pilgrimage, and the various paths usually require some careful study before you can switch over. Stannum, however, can be entered instantly, and is usually entered when some Promethean goes, "Oh, fuck this shit."
And a step below that is the path of Centimani, the Refinement of Flux. Flux is a force of dissolution and mutation, and the Centimani themselves are focused on monstrosity rather than rebirth. Prometheans on this path have not only given up on trying to be good, they've given up on trying to be anything resembling a human.
It is said that to betray the Imperium is the heretical work of Chaos. After all, the Emperor Protects, and His Imperium provides for all. So who cares if you grew up on a world with a 95% conscription rate, if your local sub-System governor cut off all incoming supplies to your desert planet because the local figurehead didn't want to marry off his only daughter to the guy, or if you only accepted the help of that one benevolent alien race in fighting off the far-less-benevolent alien race because the Imperial Guard/Space Marines wouldn't arrive for, oh, fifty years. The response will still be BURN, HERETIC, so if you'll be condemned for being a pawn of Chaos anyway, you may as well get the fun powers (and horrid mutations) that go with it.
The tieflingsnote "planetouched" humans with a bit of fiend blood in them - usually from several generations back of Dungeons & Dragons tend to fall victim to this. While they are no more predisposed to good or evil than their human kin, they're surrounded by people who can see only their fiendish heritage and therefore conclude that they must have an inherently evil nature—which leads to a cycle of abuse that drops tieflings face-first into this trope with depressing frequency. Compare their Aasimar counterparts, who sometimes get so worn down by the assumption that their celestial blood means they must be paragons of good and justice that they end up bobsledding off the slippery slope.
"I had rather be a canker in a hedge than a rose in his grace, and it better fits my blood to be disdained of all than to fashion a carriage to rob love from any: in this, though I cannot be said to be a flattering honest man, it must not be denied but I am a plain-dealing villain. I am trusted with a muzzle and enfranchised with a clog; therefore I have decreed not to sing in my cage. If I had my mouth, I would bite; if I had my liberty, I would do my liking: in the meantime let me be that I am and seek not to alter me."
Similarly, the bastard son Edmund in King Lear laments that he is categorized as base and lowly since he is "illegitimate." Since he is going to be treated unfairly regardless of how well-behaved he is, he resorts to evil to try and increase his standing.
Alright, enough! So be it! So be it then... Let all Oz be agreed: I'm wicked through and through. Since I can not succeed, Fiyero, saving you. I promise no good deed Will I attempt to do again Ever again No good deed Will I do again!
Bat Boy:"I don't want to harm you, I only want to KILL! You shall have your monster, I shall drink my fill! At last I am embracing my bloody destiny! Dear Mom and Dad this place will be The last thing that you ever see! Revenge will be a home for me!"
The most commonly-accepted interpretation of Sorceress Ultimecia's motivations in Final Fantasy VIII is that she was discriminated against and persecuted by a society conditioned to assume that any sorceress runs the risk of snapping and trying to take over the world, until - shockingly enough - she snapped and decided to become the evil sorceress that history reviled. Her speech in Deling very heavily alludes to this.
This is Odio's backstory in Live A Live. Even after the demon lord tricked him into killing the king, he figured he could still be a hero, so long as one person believed in him. When that one person committed suicide as a direct consequence of his actions, he took up the demon lord's title and role, spreading pain and misery across the universe.
In Skies of Arcadia, Ramirez's backstory involves a play on this trope. He came to Arcadia as a naive idealist with some lessons to learn from the school of hard knocks, but found one guy who seemed alright as a role-model/mentor. Sadly, he ended up getting played for a fool and humiliated when the guy turned out to be a dirtbag. So, he went on a Roaring Rampage of Revenge and gave up on his nice ideals. He was convinced that Humans Are Bastards was a universal truth and decided he might as well join them.
In Icewind Dale2, the twin Big Bads Isair and Madae were treated as embodiments of evil their entire lives because they were cambions — half devil, half elf. After a lifetime of this treatment, with a cruel prank involving cakes baked with holy water as the final straw, they decided they might as well act like embodiments of evil. Iselore the Big Good remembers that he warned their foster mother (the only person who ever loved them) that "they are forged in evil and only evil can come from them" and sadly wonders if he helped make it true.
In Dragon Age II, almost all of Kirkwall distrusts the qunari and their leader, the Arishok, due to the qunari's reputation for being heathen conquerors. While the Arishok is by no means a nice guy, he and the rest of the qunari just want to mind their own business and leave Kirkwall as soon as possible. However, after years of unprovoked attacks by those who expect him to act against them, the Arishok finally has enough and tries to conquer Kirkwall.
The Arishok: Fixing your mess is not the demand of the Qun, and you should all be grateful!
This also sums up why so many Circle mages turn to Blood Magic; they spend their whole lives effectively at the mercy of the templars, who tell them that the abilities they were born with are sinful and hold the threat of being made Tranquil over their heads, so what do they have to lose by dealing with demons? First Enchanter Orsino does this in the endgame - even if you sided with him.
Spelled out in the web series Dragon Age: Redemption focused on several characters trying to stop an escaped qunari mage, or Saarebas ("dangerous thing" in qunari). The qunari treat their mages way worse than humans. They sew their mouths shut and force them to wear harnesses that dampen their magic and can be used to shock them into submission. After finally stopping and collaring the Saarebas, Tallis asks him why he tried to cast a dangerous spell. His response is that he has been told for so long that he's a thing of evil that the only thing he could think about doing after escaping is the most harm possible. However, not all Saarebas are like that.
In Starcraft II: Heart of the Swarm, Kerrigan, recently de-infested and now aligned with the heroes, is actively trying to turn her back on her own potential to control the zerg, since she feels this might lead her back to her old self. Then, The Dominion attacks her allies, forcing her to take control of a feral zerg brood lest the Dominion shoot down her Love Interest, Raynor. She realizes during the fighting that she's at risk of giving in to her viciousness, and tries to curb herself. However, Raynor's ship never shows at the rendezvous and she overhears a news report that the Dominion captured and executed him before he could escape. (In fact, he was not executed, but is being held as a check against her attacking the Dominion.) She promptly declares bloody vengeance against the Dominion and Emperor Mengsk, actively seeking out zerg forces to command and becoming re-infested, after a fashion to increase her psychic power. Mengsk seems to realize that the whole mess is his fault (twice over; his betrayal got her infested in the first place!) when she kills him.
Redcloak of The Order of the Stick has this trait in his more sympathetic moments, most of which are in the prequel book Start of Darkness. As a member of the Always Chaotic Evil goblin race, if a "good" character murders him, any other goblins, or even any baby goblins for any reason, this is not treated as an "evil" act, even though the whole reason goblins are evil in the first place is supposedly because they murder without provocation. His example is particularly notable, as at one point he has a Heel Realization — about the way he mistreats other goblins. He never seriously considers the idea that he's giving humans any less than they deserve.
"'F-Freak?' He shot at me just for what I look like? Yeah? W-Well, if they want a monster, maybe I'll just give them one! Like Shelley's Frankenstein Monster, if I cannot give love to the world, then i will give it wrath! I'll... I'll... Aw, who am I kidding? I haven't got any wrath! Oh Dr. Poule, what am I going to do? Sob!"
It doesn't help that he's not exactly getting good publicity because even when he was trying to be explicitly heroic, he was a Hero with an F in Good. He still wants to do long-term good, even as a villain, but he's not that great at it. His plan seems to be, "1. Take over the world. 2. Everything wrong with the world magically fixes itself because I'm in charge."
Even then he was something of a Well-Intentioned Extremist who thought that he can fix the world by ruling. However, when his Morality Chain Penny dies in the end, he had nothing keeping him from becoming a true supervillain.
In Worm, Taylor ultimately decides to become a supervillain in full on the grounds that, firstly, the supervillain gang that she joined with the intent of betraying them to the heroes is composed of the only real friends she's had in over a year, and secondly that every superhero she's encountered has been a Jerkass. She continues to mostly fight villains as a supervillain, mostly because her gang is taking over the city and the other villains disagree with this.
The Ice King from Adventure Time resorts to this at times when his more diplomatic attempts backfire. Then again, considering he's often still trying to kidnap princesses...
In the Batman: The Animated Series episode, "Harley's Holiday", former Joker minion Harley Quinn espouses this after violating her parole barely moments out of being released from the asylum ("I tried to be good. I really did. But if that's not good enough, fine!"). However, after having to be rescued by Batman, she seems to reconsider.
Subverted in that most of this was Harley assuming people were acting like this to her - a dress she bought still had the tags, so the security guard was trying to take them off for her. She thought he was accusing her of stealing the dress, so in a panic she took off accidentally taking the general's daughter hostage and ran.
Oswald Cobblepot (a.k.a. The Penguin) could put up with Batman not believing he actually reformed, but Veronica Vreeland shouldn't have used him for a pig at a pig party.
Similarly in Batman Beyond, Mr. Freeze after having a new body constructed for him, decides to make amends for his previous misdeeds all those decades ago. Not many were convinced, and he even set up a charity to help the victims of his past crimes after one of them tried to kill him. Then his body starts failing, and his doctor/girlfriend decides to try and knock him unconscious and use his organs to see what went wrong. Freeze barely survives, and goes back to revenge again, killing his traitorous girlfriend, and planning to blow up the Wayne-Powers compound, threatening to kill hundreds more, with him along with it. To be fair to Bruce (who is the most suspicious of Freeze, saying "Victor Freeze lives for revenge"), in the animated movie Sub Zero, which took place decades earlier, Freeze had finally achieved his goal of saving the life of his wife and seemed to have undergone a Heel-Face Turn as a result of that (he also tells Batman and co. to save some children rather than save him when he is badly injured on an exploding oil rig). But in the following series, The New Batman Adventures, his body is falling apart and he decides that even though his wife is alive and happy, if he can't be happy with her he is going to make the lives of everyone in Gotham as miserable as possible, culminating in a Kill 'em All plot. It's understandable if Freeze isn't wholly trusted.
Mojo Jojo in The Powerpuff Girls Rule. When he becomes ruler of all, he uses his new power to make things right and pleasant. It becomes suddenly boring to him, so he reverts to villainy at the end.
An episode of Futurama had the crew make a delivery to a giant ugly monster. Bender continuously insults him, but the guy remains calm and composed and takes the barbs in gentle stride. Fry tries to be compassionate, claiming he just inherited ugly genes from his mother. Too bad insulting his mama was his Berserk Button. Later, the giant comes to Earth to try and apologize for his outburst. Unfortunately, the world's water supply had been turned into alcohol and everyone acts drunkenly agressive towards him. The giant finally snaps and goes on a rampage.
Giant: I won't stop until your whole planet is as ugly as you perceive me to be!
In the Family Guy episode "Brian: Portrait of a Dog" a homeless Brian tries begging a guy for change, but the guy assumes he's crazy. Brian gets pissed off and shows him just how a crazy dog acts.
Similarly, after spending several episodes as a Villain Ball Magnet to Quagmire, and facing gratuitous outbursts and criticisms, he snaps back at him and makes an attempt to ruin Quagmire's dream relationship for revenge. Even Quagmire exclaims he didn't think he was that low before.
Scott, the Canadian dick in South Park, was an overbearing jerk that wanted Terrence and Phillip gone, but did nothing more than that other than being a jerk to people. Everyone else calls Scott a dick because of his jerkish attitude, which eventually got to him in "Royal Pudding" after he becomes a giant:
General: You're a dick, Scott! You have always been a dick! And then you got radiation poisoning in Ottawa and now you're a GIANT DICK!
Scott: Well, you kept calling me a dick, so that turned me into a dick! And then I got radiation poisoning in Ottawa and now I'm a giant dick!
Wakfu gives us a rare inversion: Rubilax comes from an Always Chaotic Evil race of demons called Shushus, but he gets No Respect from his peers, who often mock him for being a softie and not being evil enough (despite proving that he can be quite evil), to the point that he gets fed up and pulls a Heel-Face Turn, arguing that at least humans respect him to some degree.
Kung Fu Panda Legends Of Awesomeness features Fu-xi, a cobra once defended China from other evil doers. However, the others that Fu-xi sworn to protect feared him and his kind. Their betrayal lead him to be racist towards the two-leggers.
In Avatar: The Last Airbender , this is ultimately the trigger for Azula's actions throughout the series. She believed that her mother rejected her as a monster and preferred her brother Zuko. So she dedicated herself to becoming Daddy's Little Villain, proving to both her Mother and Zuko that she doesn't need their love, as being feared is the only thing that matters. It backfires on her tragically, resulting in an epic Villainous Breakdown.