History Main / SlowlySlippingIntoEvil

* In ''TabletopGame/{{Ravenloft}}'', performing an evil deed and certain other actions result in what is called a Dark Powers Check, to see if the forces that govern the Demiplane of Dread take notice. If they do, the Dark Powers simultaneously imbue them with a blessing and smite them with a curse. These powers and curses grow with each subsequent failed check until inevitably the victim becomes a monster, perhaps even a DarkLord in their own right. The more evil the act, the more likely that the Dark Powers will take notice, with some acts,-- known as Acts of Ultimate Darkness-- being so vile, heinous and cruel that they all but guarantee the Dark Powers' attention.

* Lelouch and Suzaku in ''Anime/CodeGeass'' become more and more radical during the show's progress, although their goals were noble [[spoiler:and successful.]]

* In ''Manga/DeathNote'', [[VillainProtagonist protagonist]] Light Yagami's initial instinct upon acquiring [[ArtifactOfDeath the titular notebook]] was to eliminate all crime on Earth to create a peaceful Utopia. Towards the end of the very next episode, however, Light ends up killing a man during (what he believed to be) an international broadcast [[DisproportionateRetribution for calling him evil]]. While it turns out said man was a criminal on death row, Light didn't know that at the time. [[JumpingOffTheSlipperySlope Things only get worse]] [[ProtagonistJourneyToVillain from that point forward.]]

Sometimes you can see what you want just beyond your reach — you don't have to jump off the slope, and it's not all that steep anyway, just a few steps on TheDarkSide and you'll have it. Yet what was just a short walk in one direction is not so easily traveled in reverse. Even if you turn back immediately afterwards, you may find yourself slipping down the slope faster than you can climb your way back up! Eventually you may tire of fighting it and just let yourself continue to slide unhindered, or even worse: choosing to [[ThenLetMeBeEvil embrace the inevitable]] and [[FaceHeelTurn turn your steps in the direction of your momentum]]. Oftentimes, all the evil you do after that first fatal act makes you [[TheDarkSideWillMakeYouForget lose sight of who you were before everything]].

* In ''Manga/DeathNote'' fanfic ''FanFic/{{Fade}}'', L gets his hands on a Death Note, containing a part of the story of Kira's rise to power. Trying to stop that from happening leads to L's own StartOfDarkness as he becomes [[HeWhoFightsMonsters more and more similar]]—and arguably worse—than the killer he's trying to find.
* Harry in ''[[FanFic/TheDarknessSeries Harry Potter and the Descent Into Darkness]]'' after he hits the DespairEventHorizon when his "friends" abandon him during the Tri-Wizard tournament and, in order to ensure his survival, he begins studying [[BlackMagic the dark arts]].

--> '''Sara:''' Sara's eyes widened. "No way. Do you think it's the same guy? Is the same guy messing with your cousin and my sister? How many lives do you think he's ruined… This Wade character…"
--> '''Jasper:''' "Possibly. I mean, from what I've heard about guys like that… They stop caring who they hurt. It's complicated because they're doing it to support themselves. Still, after a while, it stops being just about that. After a while, it becomes about making as much money as they can, no matter how many people they hurt." Jasper said.
--> '''Sara:''' "Yeah, I suppose you're right." Sara sighed. "It's a shame that there are people out there who end up thinking that way."
--> '''Jasper:''' Jasper sheepishly rubbed at the back of his neck. "I think that's just what the drug trade does to people. It ruins the lives of the addicts, but it also takes away a lot of humanity from the people who get involved in selling it. It ruins their minds, too."
--> '''Sara:''' "That's pretty bleak." Sara stared back at him, astonished by what he was saying. "Still, I can imagine your cousin probably told you a whole lot of stories that taught you this, huh?"
--> '''Jasper:''' "Yeah. Once you've heard the kinds of things people like him have seen, you realize just how destructive that whole criminal underworld is for everyone involved. It's an awful business." Jasper shook his head, then turned to Sara again. "I'm gonna ask him the next time I see him. I'll ask him to tell me more about Wade."
* In ''FanFic/TheMasksWeWear'', Zuko has no qualms firing off lightning against Appa during the invasion of the Fire Nation.

[[folder:Films — Live-Action]]

* ''Gingema's Daughter'', the first book in Sergey Sukhinov's ''Emerald City'' series, is about the adventures of Corina, originally an ordinary, if somewhat lazy, girl. She starts her way as understudy of Gingema, then runs away to travel with her wolf companion. She lives by different families, usually helping them magically in secret. But gradually, she decides that BeingGoodSucks, since everybody bothers you with requests, and being feared is as important as being loved. She deceives the Woodsman to do her bidding by pretending to be the daughter of his former sweetheart and ultimately manipulates him into deposing the Scarecrow, thus becoming the ruler of Emerald City. The rulership she establishes is a CrapsaccharineWorld: there is food for free and low taxes, but do cross Corina in any way and you are dead or turned into a small animal. By the second book, she kills Ellie's parents and becomes a fully-fledged villain.
* Creator/JRRTolkien's ''Literature/TheFallOfNumenor'': It happens to the civilization of Númenor as a whole. For a long while, Númenoreans are happy and content to lead peaceful and fulfilling lives in harmony with their paradisiacal island's nature, devoting themselves to arts and knowledge and then dying at their appointed time. After several centuries they begin explore the coasts of Middle-Earth, and although they are happy to shower their inhabitants with gifts and knowledge, they cannot help but pity their "primitive" existences. After two thousand years the Númenoreans get a taste of power when they defeat Sauron's army, and they start colonizing lands, levying tribute and complaining that their "superiority" means they should be immortal, too. Their increasing hubris and greed lead the Númenoreans to create a brutal empire, and their fear to death ends up leading them to worship Morgoth, thusly completing their corruption.

* A DiscussedTrope in ''Hard Rain'' (aka ''A Lonely Resurrection'') by Creator/BarryEisler, with various characters being deliberately exposed to killing (FightClubbing being used to recruit assassins), prostitution (a stripper in a nightclub who's being offered money to sleep with clients) and espionage (a CIA informer is asked to sign for money he's being given. The first few times he might refuse or put an ineligible scrawl, but eventually he'll get careless and put his proper signature which can be used for blackmail) to desensitize them to those worlds so they can be drawn into them.
* The protagonist of ''[[Literature/HeraldsOfValdemar Brightly Burning]]'', Lan, has a hideously strong version of [[PlayingWithFire the Firestarting Gift]] which manifests in his teens. He had a TraumaticSuperpowerAwakening in which he burned several bullies to death and which left him with the perception that his powers are like some malevolent, hateful dragon curled up inside of him. Lan spends much of the rest of the book horrified by his powers and only agrees to use them when told he doesn't have to kill anyone. But Firestarting on his scale isn't good for much ''except'' killing, he works off ThePowerOfHate, and ItGetsEasier, so when he joins the war effort he abandons his scruples one by one until he and the dragon are one and the same and gleefully hunting people to burn alive, and even [[OurAngelsAreDifferent his Companion]] can't disentangle them. In the midst of his climactic SuperpowerMeltDown he no longer distinguished between ally and enemy but only wanted to [[OmnicidalManiac burn the world]], though he died in his own flames.
** Even though some of his allies saw troubling things in him towards the end, they still remember him as a hero. Since the Valdemarans got a psychic heads' up from their Forseers they managed to withdraw most of ''their'' forces in time to not get killed, and Lan is remembered as having annihilated the enemy army and ended the war in a day.
* In ''Literature/TheIronTeeth'' web serial, Blacknail the goblin starts out small and weak. At first he sticks to petty crimes such as theft, but in order to gain power in his "tribe" of outlaws he begins to kill.

* ''Franchise/StarWarsLegends'': In ''[[Literature/StarWarsKenobi Kenobi]]'', [[spoiler:Orrin Gault]] is eventually revealed to be this. He started by embezzling money from [[spoiler:the Settlers' Call Fund in order to make payments on his debts. When attacks by Tusken Raiders became rarer courtesy of Anakin Skywalker, more and more settlers canceled their subscriptions, so Orrin and his family began [[MonsterProtectionRacket staging raids to make them return]]. They never give the settlers more than light injuries, but are not above killing actual Sand People in "retaliation". At the climax, he attempts to murder Ben after the latter witnessed them faking a raid and finds out he's a Jedi in the process; even so, Ben lets Orrin go, only for the latter to [[RedemptionRejection refuse to turn around]] and plan to sell Ben's identity to the Galactic Empire. His kids don't fall far from the tree and decide to kill Annileen Calwell, who had been the family's best friend until the day before.]]

--> This business of why shouldn’t we do this, and we do it, and so then why shouldn’t we do this, and we do that, because it’s only a tiny bit more than the one before, and it would be so nice – it’s leading on and it’s not leading on, it’s like with a bag of sweets, just one more and we’ll put them away, except one more’s only just the one more, isn’t it? And they are nice, so there’s never anything against… Oh, all I mean is people forget things and lose their heads. You know how they do.

** Wilbur starts off as a genuinely well-meaning man, who is hampered by his own selfishness, short temper, and paranoia which makes him pretty unpleasant to be around. As he goes through a TraumaCongaLine after Schlatt exiles him that culminates in him realizing that [[spoiler:he's a [[AlwaysChaoticEvil Source]]]], an already unstable Wilbur snaps and [[ThenLetMeBeEvil decides to embrace what he sees as his true nature.]]

* A major theme of ''Literature/Overlord2012'' is that Ainz Ooal Gown, despite starting out as an AntiHero or AntiVillain, is slowly becoming just as much of a ruthless, bloodthirsty tyrant as his underlings and the rest of the world see him as. Interestingly though, in the setting he is in he still can be seen as a good guy.

** Blake describes this happening to Adam Taurus, her ex-boyfriend and former partner from the White Fang. The character short/flashback from Volume 6 shows that his first time killing someone seems like a genuine case where he accidentally went farther than intended in a fight, was done to protect someone else, and that Adam appeared ashamed of himself afterward and surprised when [[WellIntentionedExtremist Sienna Khan]] and others applauded him and called him a hero for what he did. From there it quickly escalated, with a strong implication that Sienna enabled his violent tendencies without realizing that as time went on he was became more motivated by a desire for power and a bitter hatred of humanity than by the desire to help his own people. Soon he was killing or ready to kill freely in the heat of battle, even when it wasn't necessary, and by the time of the Blake Trailer just before Season 1, Adam was killing (or trying to kill) people out of simple bloodthirsty spite. While her claims are somewhat suspect given her own bias and the way Adam manipulated and gaslit her (perhaps for ''years''), ''VideoGame/RWBYAmityArena'' would reveal he legitimately was once an idealistic young boy once who wanted equality, but that changed after he was [[FacialHorror horrifically branded on his face]] and [[EyeScream eye]], which gave him an obsession with revenge and a desire for Faunus supremacy instead of equality with humanity.

* A major fear for the kids in ''Literature/{{Animorphs}}''.

** [[TabletopGame/TheDresdenFiles The roleplaying game]] reflects this by giving Lawbreakers mandatory stunts that cost them refresh whether they like it or not but [[ItGetsEasier provide them with bonuses towards breaking the same laws again]]. Of course, they technically never ''have'' to use those bonuses (which come with additional drawbacks if one keeps taking advantage of them anyway, literally changing who the character is over time as he or she gets twisted by the ongoing practice of forbidden magic), but once things get desperate and the temptation great enough...?

* Made explicit in CS Lewis' ''Literature/TheScrewtapeLetters'', which is a satirical exploration of Christian theology, detailing a senior demon's advice to his nephew on securing the damnation of a human -- ''the safest road to hell is the gradual one -- the gentle slope, soft underfoot, without sudden turnings, without milestones, without signposts''.

** Blake describes this happening to Adam Taurus, her former partner from the White Fang. At first, when he killed someone, they were accidents, which soon became acts of self-defense, and by the time of the Blake Trailer, Adam was killing (or trying to kill) people out of spite. While her initial claims are suspect given her own bias, ''VideoGame/RWBYAmityArena'' would reveal he legitimately was an idealistic young boy once who wanted equality, but that all changed after he was [[FacialHorror horrifically branded on his face]] and [[EyeScream eye]], which led him to wanting to get back at humans for Faunus. The Volume 6 Character Short shows that his first kill, done to protect the original High Leader Ghira from a racist human, was made in a fit of battle passion after he non-lethally subdued the other human attackers. While he did show ''some'' shame over it, he was more surprised when Sienna, Ghira's eventual usurper, applauded his actions. It's strongly implied that Sienna enabled his violent tendencies without realizing he was becoming more motivated by power than by helping Faunus.
** James Ironwood initially started the series being a member of the BenevolentConspiracy committed to fighting the evil plaguing the world. However, as time goes on and he suffers more defeats and trauma, he slowly begins taking more ruthless and extreme actions, becoming HeWhoFightsMonsters. At one point he expresses his belief that Salem's greatest advantage was her own LackOfEmpathy. By the end of Volume 7, he has no problem murdering any who dispute his methods, and by the tail end of Volume 8, he goes so far as to [[spoiler:threaten to blow up a city]].

* In the ''Franchise/SpiderMan'' fic "[[https://archiveofourown.org/works/49689625/ Jackpot]]", Spider-Man bluntly informs Tony Stark that he's coming at least dangerously close to that line, considering that he's actually used technology from the Smythe family to create a "Spider-Slayer" armor specifically to fight the wall-crawler when Stark has no evidence that Spider-Man is doing anything more than securing his anonymity so that he can help people outside of the Registration Act.

* While the morality of Dark Magic in ''WesternAnimation/TheDragonPrince'' depends on what side of the continental divide you live on (humans tolerate it since it's the only [[spoiler:apparent]] way they can use magic, while elves and dragons see it as an abomination), most of its practitioners start using it for larger and more monstrous spells the longer they have access to it. [[BigBad Viren]] initially used it for the greater good, sacrificing the heart of a rock titan to save his nation from a famine, but by season 3 he was using Dark Magic to forcibly upgrade innocent soldiers into monsters to give him an opening to kill the titular Dragon Prince, [[WouldHurtAChild a hatchling]], for no other reason than he wanted to use the Dragon Prince as a power booster.
* Catra in ''WesternAnimation/SheRaAndThePrincessesOfPower'' starts out as a villain, but comes across as more indifferent to the consequences of her actions than outright malevolent, and she retains sympathetic characters given her FreudianExcuse and complicated relationship with Adora. Unfortunately, her [[GreenEyedMonster out-of-control jealousy of Adora]] and [[TroubledAbuser inability to process her emotions constructively]] lead to her becoming steadily worse: going from trying to recover Adora to trying to kill her in order to [[AlwaysSecondBest move out from under her shadow]], getting crueler and more selfish, and eventually [[spoiler:trying to destroy the world rather than give Adora another victory]].

*** Anakin Skywalker undergoes this throughout the series. As the seasons wear on, he slowly becomes more ruthless and willing to PayEvilUntoEvil. All part of [[BigBad Palpatine's]] plan, of course, since he wants Anakin as his next Sith apprentice.
** ''[[WesternAnimation/StarWarsTalesOfTheJedi Tales of the Jedi]]'': Episodes 2-4 focused on Count Dooku's gradual decline into evil, following him as he goes from a valiant and noble Jedi Knight to an embittered political idealist to a ruthless Sith Lord who will do anything to bring order to the galaxy.

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