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[[quoteright:230:[[ComicBook/XMen http://static.tvtropes.org/pmwiki/pub/images/sod_4765.jpg]]]]
[[caption-width-right:230: A boy and [[SelfDemonstrating/{{Magneto}} his future self]].]]

->''"A child is born to innocence. A child is drawn towards good. Why then do so many among us go so horribly wrong? What makes some walk the path of darkness, while others choose the light? Is it will? Is it destiny? Can we ever hope to understand the force that shapes the soul?"''
-->-- ''Series/{{Heroes}}''

[[RousseauWasRight Nobody is born evil]] (well, except maybe the EnfantTerrible). Something usually happened to push a villain down the path to [[{{Villains}} villainy]]. And hey, mightn't that make an interesting story?

Thus, we have the Start of Darkness, a {{Prequel}} DarkAndTroubledPast where we find out how the main antagonist from the original story got to that point.

This, naturally, is especially common with {{Fallen Hero}}es, who usually get a DownerEnding where they lose faith in themselves and/or humanity. This will be especially poignant if they UsedToBeASweetKid (see also: FreudianExcuse).

Keep in mind that the reasons [[DisproportionateRetribution aren't always good ones]], if there is such a thing as a good reason for turning evil.

Much of the plot is often a ForegoneConclusion, often ending in TheBadGuyWins or PyrrhicVillainy; many characters are DoomedByCanon, which may require a full KillEmAll to explain why they don't show up in the original work. May include a BloodbathVillainOrigin to signal the first emergence of the character's villainous side.

Badly executed, this can be a part of a BadassDecay.

Please note that this is about '''{{prequel}}s and [[FlashBack flashbacks]]''' that show a major villain's reasons for turning evil. If this is the subject of the main plot, you're watching a ProtagonistJourneyToVillain.

Subtrope of FaceHeelTurn, which is when a good guy turns bad.

The Trope Namer is ''Webcomic/TheOrderOfTheStick'' prequel ''Start of Darkness'' (see "Webcomics"), whose title is itself referring to the 1899 Joseph Conrad novel ''Literature/HeartOfDarkness'', which tells the story of the protagonist's journey down the Congo river to rescue the mysterious Mr. Kurtz, an experience that changed his entire outlook on life for the worse.

'''Needless to say, this being a {{Prequel}} trope: Spoilers Ahead!'''

[[noreallife]]
----
!!Examples

[[foldercontrol]]

[[folder:Anime & Manga]]
* In ''Manga/YuYuHakusho'', the BigBad antagonists in seasons one and two are shown to have become villainous due to major psychological trauma leading to crises of faith in their formerly-held ideals (the massacre of Toguro's students by a youkai and Sensui's exposure to the depravity of humanity and then the Black Chapter tape). And in both cases enough self-hatred to stage really stupid, selfish [[spoiler: [[ThanatosGambit Thanatos Gambits]].]]
* ''Anime/MazingerZ'': Hell's mind was already unstable and unsound cause his upbringing (he was abused by everybody when he was young, including his parents. Particularly her mother often spouted she never wanted having children and she would be better off without him; and she was not above of hiting him for no reason). However, when he found out the woman he loved was in love with another man [[spoiler:Juzo Kabuto, future builder of Mazinger-Z and [[TheHero Kouji]]'s grandfather]], he... [[LoveMakesYouCrazy flipped out]] and [[LoveMakesYouEvil attempted to murder his perceived rival]]. Shortly after he tried helping someone... and he got the crap beaten out of him for it. Later he was crawling back towards his home, bruised and blood-stained, muttering "Mediocre imbeciles! You don't deserve being alive! One day I'll purge the world off all of you! And then everybody will have kneel before me". When you heard his words and saw his utterly mad stare you realized he had snapped out completely and Dr. Hell had been born.
** Let's tell people had shunned him out of scorn before, but after that point they did it out of FEAR.
* The ''[[RozenMaiden Rozen Maiden Ouvertüre]]'' OVA explores the start of Suigintou's fierce rivalry with Shinku and the source of her massive inferiority complex that motivated her to become the first season's BigBad.
* The [[http://www.youtube.com/watch?v=XOBG3CCew7Q 8th and final Parallel Works video]] for ''Anime/TengenToppaGurrenLagann'' is one of these for [[spoiler:Lordgenome]].
* "Two Father's Little Soldier Girls", the 21st episode of ''Manga/BlackLagoon'' contains a number of flashbacks to [[MagnificentBastard Balalaika's]] past detailing her childhood, service in Afghanistan, disillusionment with society and rise to power in [[TheMafiya Hotel Moscow]].
* ''Manga/AxisPowersHetalia''
** "Hey, Lithuania, we don't want children that can't play nice, [[http://community.livejournal.com/hetalia/1045.html right?"]]
** Russia mentions all [[CosmicPlaything he's endured over the centuries]]. This could be taken as his DespairEventHorizon, when he simply couldn't take ''more''.
* Almost every ''RaveMaster'' villain gets at least a chapter for this. Some are a little sad, some will leave you temporarily cheering for the villain (until you remember that every single one aims to wipe out all life as we know it).
* One episode of ''Anime/RahXephon'' presents the back-story of Makoto Isshiki, an EvilAlbino who is a cold-hearted seducer and major jerk to everyone else. It shows him as a cute and kind boy who just wanted to find his parents. Then, one day he admitted to himself [[CloningBlues what he really was]], and his flashback ends with him getting an ImportantHaircut and taking on his nasty personality.
* ''Manga/OnePiece'' has Chapter 0, a special tie-in to the tenth movie. In it, we see Shiki and Gold Roger's rivalry, as well as the Flying Pirate's escape from Impel Down and his preparing for the movie's plot. Interspersed are scenes of people throughout the world, reacting to both Roger's death and Shiki's escape.
** To a lesser extent, the Fishman Island arc explains part of what made Arlong who he is.
* One episode in the second season of ''Anime/GhostInTheShellStandAloneComplex'' focuses entirely on [[AntiVillain Kuzes]]' past, showing what motivated him to fight on the behalf of the people, even against the state.
* ''Anime/GaReiZero'' is [[WordOfGod explicitly stated]] to be the Start Of Darkness of Yomi. Judging from [[WoobieDestroyerOfWorlds what happen]] [[Manga/GaRei in the manga]], this might also qualify as Kagura's Start Of Darkness.
* ''Manga/ElfenLied''. Sure, [[KidsAreCruel brats]]. Go ahead and beat to death the puppy of the [[ShrinkingViolet shy]], [[TheWoobie emotionally-repressed pink-haired girl]] [[ApocalypseMaiden with horns]] and force her to watch -- [[SarcasmMode she can't hurt you]].
* ''Manga/{{Naruto}}'' has done this with many antagonists so far, and attempts to justify the [[spoiler: Uchiha examples, by claiming that their powers take hold of them because they love ''too much'']]:
** Deuteragonist Sasuke Uchiha witnessed his brother Itachi murder their parents, after murdering their entire clan. He then was subject to days of MindRape compressed into seconds, and a challenge to kill his brother when he's ready. None of this makes him "evil", so much as focused on killing his brother, a world-class criminal, on his own. After months of being shown up by his rival, Sasuke gets reminded by Itachi again that he's insignificant. He then follows Orochimaru, the series' first BigBad, to gain the power to beat Itachi. After he finds out [[spoiler: the truth about Itachi's backstory, that it was the clan itself that was evil and Itachi was just following orders, he begins to show signs of mental imbalance, playing into the hands of the new BigBad manipulating him, Tobi]], and he decides his best option is revenge on their entire home town.
** Gaara grew up believing his mother named him as a curse against everyone else, for her having to die in childbirth. His father had warriors and himself to keep Gaara in line, because of the demon sealed within him, which would be unleashed if he lost control of his emotions or even slept. As a small child, he believed that there was only one person who loved him, his maternal uncle Yashamaru. [[DespairEventHorizon The betrayal of Yashamaru]] transformed him [[BreakTheCutie from an attention-starved waif to serial killer]]. He came around to the side of good once he realized what friendship was, long before any of the above was actually fixed, and years before it was all retconned to be [[spoiler: a big misunderstanding, and his parents always loved him]].
** When [[spoiler: Sasuke "defeated" Orochimaru]] the manga briefly touched on [[spoiler: Orochimaru]]'s past, while the anime expounded on it. His [[TragicDream deepest dream]] was to live long enough to meet his parents when they were reincarnated. Years of war and loss turned him cold and bitter until only the dream of living forever remained.
** [[spoiler: Nagato]] lived in a state of constant war, as his homeland was the battleground for all the bigger countries' wars. For years, he was subtly manipulated and watched by [[spoiler: Obito as Tobi, and Madara as Black Zetsu]]. Then, his parents were killed in front of him. Eventually, [[spoiler:the death of his dear friend Yahiko and his subsequent crippling]] drove him to share his Pain with the rest of the world.
** [[spoiler: Kakuzu]] was imprisioned and punished for failing to kill the First Hokage. As a result [[spoiler: he steals the elders hearts and runs away.]]
** [[spoiler: Kabuto]] grew up an orphan, but that didn't let him get down. However, he never really knew who he was meant to be. He was inspired to be a ninja by the first people to challenge him to grow in his natural talents, [[spoiler: Orochimaru and Danzo]]. While on a mission for them, he was tricked ''by them'' into accidentally killing his foster mother, who in turn had failed to recognize him due to their brainwashing of her. After this happens he hits the DespairEventHorizon and [[spoiler: Orochimaru]] was the only person around that was there for him at that point. He commits some good, and a lot of evil, actions for the rest of the series, but only comes into his own once [[spoiler: Orochimaru dies]] and he no longer has any guidance or kindred spirit.
** [[spoiler: Obito Uchiha]], after some subtle mental influencing by [[spoiler: Madara]], witnessed first-hand the death of [[TheLostLenore his childhood crush]] at the hands of the friend who vowed to protect her and became convinced the world he lived in was hell. [[spoiler:He then decided to accept Madara's plan to create a better world by killing or brainwashing everyone in the world]].
** [[spoiler: Madara Uchiha]] lived through a time of warfare, like everyone else in his generation. Then, thanks to his best friend's work, which he attempted to co-opt and sabotage, things started getting better and he mostly got over the wars, like everyone else in his generation. Then this one time, he didn't get to be the top boss of the country, after he eavesdropped on a private conversation between his best friend and his best friend's brother, where he found out that not everyone liked him, because he was such a bully to other people, his own family, and the people they were supposed to be courting as allies. So instead of being happy for his friend who did get the job, he [[spoiler: used an ancient stone detailing the world's constantly warring history to assume said friend's system would fail and justify his becoming the BigBad and trying to brainwash or kill everyone in the world, despite that in no way saying he in particular should take any action]]. Ladies and gentlemen, your final villain.
* The flashback arc in both incarnations of ''{{Trigun}}'' seems at first to be the background for the highly [[MysteriousPast mysterious]] lead, but it's even more about the Start Of Darkness for the BigBad, his EvilTwin. In the anime version, the kid was always somewhat [[CreepyChild touched in the head]], and one [[FantasticRacism abusive crewman]], combined with the awareness that the human race destroyed the Earth and are [[HumansAreBastards now looking for a new planet]], push his pragmatism into KillAllHumans territory. In the manga...he has ''[[StrappedToAnOperatingTable much]]'' [[TheyWouldCutYouUp better]] [[TheReveal reason]].
** His ''manga'' [[AndIMustScream reason]] made ''Vash'' try to ''kill himself twice'' and laugh hysterically when he thought he'd accidentally killed [[HappilyAdopted Rem]]! And manga Knives UsedToBeASweetKid--more than Vash, even. Some of adult Vash's ideals are stuff ''Knives'' said as a kid.
** Legato also gets one of these, in the manga. Unusually, it has a very upbeat ending -- because psychotically serving an OmnicidalManiac who doesn't really give a damn about you is ''so'' much better than being raped to death by the guy who owns you. Knives didn't just spare him, he even [[TearJerker asked his name]]! Weirdest CrowningMomentOfHeartwarming ever. And nameless-boy-who-would-become-Legato goes stumbling after him naked and weeping for joy.
** Livio has one, too, although his is complicated by the fact that [[spoiler: first he got a psychotic alternate personality,]] and then later he was [[spoiler: acquired by the Eye of Michael and turned into a killing machine in his own right.]]
** Anime [[AntiHero Wolfwood]] also gets one. Manga Wolfwood just gets back story snippets. But because the anime is LighterAndFluffier, Wolfwood's philosophical position has a lot less pull there, so he needs a more clear-cut 'reason' to think the way he does.
* ''RomeoXJuliet'' practically drops it line for line with the episode "Darkness: The Origin", which gives Prince Montague a somewhat run-of-the-mill FreudianExcuse.
* 2007 adaptation of ''SkullMan'' features one for [[spoiler: Black Ghost, BigBad of {{Cyborg009}}]]
* Episode 11 of ''LastExileFamTheSilverWing'' shows the event that ended up shaping Luscinia Hafez into the series' BigBad.
* ''{{Berserk}}'' Golden Age Arc serves as one for [[spoiler: Griffith/Femto]], villain who was previously seen once, right before the arc started.
* ''[[Anime/PokemonTheFirstMovie Pokémon: The Origin of Mewtwo]]'' is this to... ...guess who.
* ''FateZero'' is one for Kotomine Kirei.
* ''MutekiKanbanMusume'', being a DeconstructiveParody of the {{Shonen}} FightingSeries, has this in the short '' "Another Kanban Musume" '': Megumi has an extended FlashBack when she tells the story of how in [[FreudianExcuse her childhood she tricked a teacher into teaching her]] under a TrainingFromHell how to gain ImprobableAimingSkills so Megumi can defend herself against Miki Onimaru. The parody here is that Megumi is not a ClassicVillain nor Miki is TheHero. They both are only the SchoolyardBullyAllGrownUp and TheRival on each other. The deconstruction is that this story is not about ImprobableAimingSkills, because Miki always manages to DodgeTheBullet. Megumi is really talking about how she realized [[CantCatchUp that she was weaker than Miki]], [[SillyRabbitIdealismIsForKids and how she renounced to attack directly against her and resorted to lie]] and be the {{Schemer}} to fight her… only Megumi doesn’t realize that, because she is an {{Hypocrite}}.
* Subverted in episode 10 of ''Anime/PuellaMagiMadokaMagica''. It seems to be one of these for Homura, but instead, it ends up showing that she's far less villainous than she seems [[spoiler:(all of her AntiHero antics are an attempt to prevent Madoka from dying and/or suffering a FateWorseThanDeath)]]. Played Straight for Kyoko in episode 7.
* ''Anime/TheUnlimitedHyoubuKyousuke'', episodes 7-8, for the VillainProtagonist, Kyousuke. Sort of a weird case because the flashback is almost entirely upbeat-ish; most of the tragic stuff is {{Time Skip}}ped over. Only the final push where [[spoiler:the captain]] shoots Kyousuke because he was supposedly going to destroy the world, [[NiceJobBreakingItHero but the assassination attempt fails to kill him and turns him evil]], is actually shown.
* In episode 15 of ''Anime/GuiltyCrown'' ''[[TheHeart Shu]]'' of all people has one of these. [[spoiler: Hare]] is killed right in front of him (in his arms) because of something stupid and selfish done by [[spoiler: Souta and his friends]] in order to prevent [[spoiler: the creation of the Void Ranking System.]] After [[spoiler: her]] death Shu gets DullEyesOfUnhappiness and [[DoesThisRemindYouOfAnything mounts Inori and forcibly removes her Void]] and procedes to chillingly emotionlessly systemetically rip to pieces the mechs attacking them. He then proceeds to go hysterical and begin pounding [[spoiler: Souta's]] face in before being dragged off by Yahiro. [[DespairEventHorizon His next words,]] [[OOCIsSeriousBusiness coming from]] Shu of all people, [[OhCrap hit the characters(and the audience) pretty hard]]:
--> '''Shu''': "I was wrong. Kindness is pointless. We have to separate the good from the trash. I'm going to become king." ''[[FanNickname Heil Mein Shurer]]''
* ''Manga/DeathNote'' After Light realizes what he posses, he decides that he enjoys having the power to kill those he views as evil. He even jumps the gun and starts his GodComplex after he finally meets Ryuk and tells him about his intentions.
[[/folder]]

[[folder:Audio Play]]
* Yet another Start of Darkness for the Master in the ''AudioPlay/BigFinishDoctorWho'' audio drama ''Master''. Apparently, it all goes back to when he and the Doctor were at the Academy, and he killed an older boy who was tormenting them. [[spoiler: This isn't what happened. The Doctor killed the boy and then made a deal with Death for the guilt to be transfered to his friend.]]
%%% Please don't link the below with Big Finish Doctor Who. I, Davros is a Doctor Who spinoff.
* The audio drama series ''I, Davros'' shows the early life of everyone's favourite [[Series/DoctorWho Dalek creating]] MadScientist. Interesting in that he isn't given any FreudianExcuse, and you don't gain any sympathy for him, just understanding.
[[/folder]]


[[folder:Comic Books]]
* The Franchise/{{Batman}} Graphic Novel ''Comicbook/TheKillingJoke'' is a Start of Darkness story for SelfDemonstrating/TheJoker. Just [[MultipleChoicePast one of several]], in fact.
** The issue ''MadLove'' of ''ComicBook/TheBatmanAdventures'' is also partially a Start of Darkness story, this time for Harley Quinn. It explains who she was and how she ended up with the Joker.
* A large portion of ''ComicBook/GoldDigger'''s 75th issue was dedicated to Gina and company discovering the origins of both Alfred Peachbody (who was less noble in his beginnings) and Dreadwing, who fits this trope to an absolute T. Though Dreadwing's origins are detailed as mentioned above, it's further fleshed out in the ''Dreadwing's Myomior'' special, which is essentially Dreadwing's past narrated by himself. Arguably effective despite the repetition, as the unbiased depictions of events from earlier serve to highlight the twisted perspective Dreadwing views his past through. It manages to make him sympathetic and tragic, while simultaneously keeping him a MagnificentBastard in the present.
* ''{{Preacher}}''
** The ''Saint of Killers'' miniseries, which explained how the titular killer became the ImplacableMan he is in the series proper. When he first appears, we know he was already a killer in the Civil War, but not how he got that way. Part of the miniseries shows his softening and becoming a family man. However, after a delay due to ruffians led to his family dying of fever, he returned to his killing.
** Herr Starr, the BigBad, has his own issue of this, as well, showing how he rose to the position that readers see him in. He gets a PetTheDog moment and a legitimate claim to having been a good guy at one point -- and quickly shows the predilections that make him such an outstanding villain for the rest of the series.
* ''ComicBook/FantasticFour'', Annual #2, showed the Start of Darkness for DoctorDoom. Reprised in a mini in recent years called "Books of Doom", with added [[DarkerAndEdgier hardcore edge]].
* While the ''KnightsOfTheOldRepublic'' comic series is mostly Zayne Carrick's story, in its background it deals with the Jedi duo of "the Revanchist" and Alek, showing their gradual transformation into the Revan and Malak we see in the game. In fact, this trope is so pervasive that Zayne himself and his Master Lucien were speculated to be a past version of every Sith Lord from the two games at some point.
* The ''JudgeDredd'' supervillain Judge Death has his origin given in "Young Death -- Boyhood of a Superfiend". This shows (with some incredibly black humour) how a nasty and psycopathic child develops into a monster that wipes out his whole world. (Although, to be fair, the reoffending rate is to all intents and purposes negligible.) Darkness hardly begins to describe it....
* In IDW's ''[[TransformersOngoing Transformers]]'' material, ''Megatron Origin'' details the origins of... [[ExactlyWhatItSaysOnTheTin guess who.]]
** ComicBook/TransformersMoreThanMeetsTheEye: Has the Shadowplay arc, which is being told to a comatose Rung to help Jog his memory. It's about Orion Pax (Optimus Prime) fighting down the corrupt Pre-war senate who seek to kill a bunch of bots, with the help of a non-corrupt senator and ragtag police crew. At the very end of the arc it's revealed that [[spoiler: it's the Senator's start of Darkness, taking the fall so Optimus and his partner get out, and having his emotions destroyed and appearance altered forever, and this was the story of how Shockwave came to be who he is now.]]
* The gradually unfolding back story of Winnowill and Two-Edge rather took over the second major arc of ''ElfQuest''. We got to see exactly how and why both ended up such raging twisties.
* ''Comicbook/{{X-Men}}'' villain {{Magneto}} has a truly long and harrowing SOD that was revealed in snippets throughout the years following his debut and would be truly over-the-top if everything about it wasn't mostly [[TruthInTelevision grounded in reality]]. It's far too long to fully recount here, but let's just say that it isn't too surprising that someone who witnessed first hand the evils of NaziGermany, the Holocaust, [[GloriousMotherRussia the Soviet Union]], and RedScare stricken America while losing his whole family, a girlfriend, a wife, and a daughter along the way as well as finding out he's a [[FantasticRacism mutant]] in the MarvelUniverse would end up a WellIntentionedExtremist.
** After decades of speculation, ''First X-Men'' showed readers Sabretooth's start of darkness. While [[AntiHero Victor Creed was never that nice a guy]], what finally pushed him over the edge into full-blown villain territory was the death of his girlfriend Holo. Holo was a member of a ragtag rebel band of mutants that Wolverine and Creed had put together, and after a while, Creed wanted the two to throw a ScrewThisImOuttaHere before the final fight to keep Holo safe, but she would not have it. Sure enough, she dies. What probably made it worse is that, while she was dying, she used her powers to show Creed the life they could've had, with the two growing old and happy together, before cutting the illusion to reveal that she was in fact mortally wounded. Creed ends up blaming Logan, and to this day, makes it a tradition to kill any woman Logan is involved with.
* "Tales of the (X) Corps" strips in ''GreenLantern'' and ''GreenLantern Corps'' show the Starts of Darkness of various Sinestro Corpsmen and Red Lanterns, as well as Agent Orange. Some of them have tragic pasts, others (including Larfleeze) just aren't very nice people.
** All Red Lanterns have tragic backstories—at the very least they were betrayed by their fellow gangmembers—because the red power comes from rage, hate, and resentment.
* ''[[Franchise/FridayThe13th Friday The 13th: Pamela's Tale]]'' by Wildstorm.
* ''[[Franchise/TheFlash Reverse Flash: Rebirth]]'' tells the origin story of Professor Zoom, the SilverAge EvilCounterpart of the Flash. The story manages to showcase, via time travel, both what a nutter he ''was'', and what a ''nutter'' he became. Long story short -- he was a child of the BadFuture where [[TheWorldIsAlwaysDoomed The Earth Is]] ''[[AvertedTrope Never]]'' [[TheWorldIsAlwaysDoomed Doomed]], so he kind of started... acting out.
* ''[[ComicBook/{{Shazam}} Captain Marvel]]'': BlackAdam's turn to darkness was explored in a trip to the past. He used to be a champion to his people called Mighty Adam and was every bit the hero. Then a supervillain killed his family. He hasn't been the same since. [[spoiler:History repeated itself in ''ComicBook/FiftyTwo''.]]
[[/folder]]

[[folder:Fan Works]]
* The JackieChanAdventures fic ''FanFic/QueenOfAllOni'', is all about Jade's [[SuperpoweredEvilSide Queen persona]] re-emerging, and her desire for power driving her further into the realm of dark magic.
** A series of flashbacks document [[BiggerBad Tarakudo]]'s own [=SoD=] — he was a human warrior who [[DealWithTheDevil sold his soul to the Oni]] for a chance at revenge against the enemies who wiped out his family. After his death, he became an Oni himself, was made a General, and eventually [[TheStarscream overthrew the Oni Elders and their Matriarchy system]].
* The ''FanFic/PonyPOVSeries'' has the Origins arc, which shows the backstory of Celestia, Luna, and Discord, and therefore serves as the latter's Start Of Darkness. [[spoiler: Discord was [[TroublingUnchildlikeBehavior never quite right to begin with]], as it's shown that the draconnequi were like the Shiva of TheMultiverse, performing {{Cosmic Retcon}}s in order to prevent worlds from ending, with Discord enjoying it far more than his siblings, who were only doing their jobs. That being said, in the grand scheme of things he was just a bully and a brat -- until an act of defiance on Celestia's part triggered a series of events that not only led to Discord embracing his sadism, but began a war between the Alicorns and Draconnequi, during which he was further [[EvilMentor mentored in evil]] by the [[FallenAngel Fallen Alicorn]] [[{{Satan}} Morning Star]]. When the war ended, Discord was reborn in Equestria as a mortal (along with Celestia and Luna) with no memory of his past existence, leading to him becoming an odd, but ultimately kind-hearted being... until his true personality resurfaced and consumed his good one.]] From that point on, he was the BigBad from canon and the rest of the series. Oh, and bonus points, it's shown at the end of the arc that when the Princesses defeated and sealed him away, his last act was to plant the seeds of doubt that led to Luna becoming Nightmare Moon. So he's responsible for ''her'' Start Of Darkness too!
** We get to see Diamond Tiara's Start of Darkness occur as the story progresses, with the primary BreakTheCutie process happening during the Mind Games arc. By the time it's done, Discord's succeeded in breaking her so fully that she [[spoiler: goes ''[[SuperpoweredEvilSide Nightmare]]'']] and becomes his [[TheDragon Dragon]].
** "Fading Futures" was a [[RecursiveFanfiction fan-made]] ending to the (at the time) unresolved BadFuture, that involved [[spoiler: Twilight Sparkle becoming the [[HeWhoFightsMonsters vengeance-crazed]] [[SuperpoweredEvilSide Nightmare Purgatory]]]] and then having a HeelRealization. However, when the BadFuture was officially revisited in the Dark World Series, it was eventually revealed that [[spoiler: the BiggerBad is Purgatory's evolved form Paradox]], at which point Alexwarlorn (the primary author) released an altered version of "Fading Futures" called "A Fading Future", edited so that there was no HeelRealization [[spoiler: and showed Purgatory/Paradox starting her [[GroundhogDayLoop revenge plan]]]], making it a proper SOD.
** Chrysalis' start of darkness is covered as an addendum during the short arc that followed the end of Dark World: [[spoiler: back at the Dawn of Time, a younger and more HotBlooded Cadence became [[KnightTemplar convinced that magic was inherently evil]] and tried to kill Amicitia (the Magician Alicorn) in order to prevent its existence. After Amicitia nearly killed Cadence in self defense, Cadence's Light of Existence went to live a mortal life to teach her how wrong she was, leaving behind her Shadow of Existence... which, against ''every'' rule of the POV universe, somehow clung to sentience and a sense of self through sheer [[TheDeterminator force of will]]. Pandora was impressed enough by this that she helped the Shadow gain its own Light, turning it into Chrysalis, who was sent into the mortal world.]]
*** And then there's her OriginsEpisode, which shows her childhood [[spoiler: after being reborn]] and how she eventually became Queen of the Changelings by killing their previous Queen, Cocoon.
* In the ''Anime/PuellaMagiMadokaMagica'' doujin, [[http://danbooru.donmai.us/pool/show/2862 "I'm working at a mahou shoujo recruitment company, but I think I may be at my limit"]] by Momiji Mao (NSFW warning for ads, since the doujin in question is on Danbooru), Kyubey is a worker at a magical girl recruitment company and down on his luck, such that his boss is threatening to terminate him if he keeps dragging down the company. The only people who believe in him are his wife Kyuko, who is three months along with Kyubey's baby, and his work buddy Kyuzo, the only one in the workplace who knows he is trying his best. Bolstered by this, Kyubey works extra hard, even pulling all-nighters, and manages to get ''ten'' new magical girls into the fold. But then it's revealed that [[spoiler:not only did Kyuzo screw Kyubey over by taking all the credit for his accomplishments, but when Kyubey calls Kyuzo up and demands an explanation for this shit, that's when he (and we) learn that this isn't even the half of how Kyuzo's betrayed him -- Kyuzo is in bed with Kyuko when he gets the call, and it turns out that he's been banging her on the side for at least three months, because that kid that's three months along? It's not Kyubey's. With everything good in his life taken away from him in one fell swoop, Kyubey snaps and goes postal on everyone before burning his workplace down. He makes a resolution that the next time he meets someone, he should give them the same cruel lesson that he believes Kyuzo and everyone else were trying to teach him]].
* We also see this trope in another Madoka fanfic, ''FanFic/StarsAbove'' a crossover with LuckyStar. [[spoiler:Homura first explains the Start Of Darkness of her timeline's Kagami in Chapter 3, but we see in happen via a WholeEpisodeFlashback in Chapter 9.]]
** By the same author, there's ''FanFic/{{Respect}}'', [[spoiler:which shows how [[TheCutie the sweetest]], [[ShrinkingViolet most timid]] character of [[SmilePrettyCure her respective series]] goes from bully-bait to MagicalGirl to [[FaceHeelTurn rampaging villain]].]]
* In ''Fanfic/ThroughADiamondSky'', Clu is a {{Jerkass}}, but not the dog-kicker of the film. At the end of the story, he's [[spoiler: turned the torture devices from the Resource Hog base into the "repurposing" racks and uses the captured Hogs as the first test subjects]].
** It's also the fact that he was jealous of his creator when it came to Jordan, saw that the Isos [[spoiler: could reproduce, and saw Kevin and Jordan being in awe of the new Iso child.]] Having Tron blow off his fears and scold him didn't help.
* There's a {{Tumblr}} roleplay that crosses over ''Film/XMenFirstClass'' with the alluded-to-in-canon 1960s era of ''ComicBook/{{Watchmen}}'', which means that Magneto and Mystique's fall to villainy is played out right alongside, and in some cases interactively with, Ozymandias and Rorschach's own slides into AntiVillain status.
* ''FanFic/InnerDemons'' is one for [[FaceHeelTurn Twilight Sparkle]], but the [[BigBad Queen of Darkness']] legacy is revealed to go back further than that. The original Queen of Darkness was an Alicorn named Midnight who was spawned in [[{{Hell}} Tartarus]], but upon seeing the light and beauty of Equestria, fell in love with it and eventually became its benevolent queen. Then the denizens of Tartarus tracked her down and demanded that she become their ruler and destroy Equestria. This caused Midnight's subjects to betray her, which in turn caused her to become the Queen of Darkness and try to destroy her former kingdom, until the pony who would become known a [[TheChosenOne the Master of Harmony]] rose up against her and destroyed her with the Elements of Harmony. With her last breath, Midnight swore to return and have her revenge, and eventually she was reincarnated as Twilight Sparkle, who in turn was therefore [[BecauseDestinySaysSo destined from birth]] to become the next Queen of Darkness.
* FanFic/TheNuptialverse has "[[VillainEpisode Metamorphosis]]", which explains the origins of Queen Chrysalis. She was originally one of [[Recap/MyLittlePonyFriendshipIsMagicS2E13HearthsWarmingEve Commander Hurricane's]] chief lieutenants, but [[FantasticRacism her refusal to make peace with the other tribes]] and personal thirst for power led to her being kicked out. She then made a [[DealWithTheDevil deal with Discord]] to gain great power, which he twisted to make her the first changeling and his [[TheDragon dragon]]. She and the changelings were [[SealedEvilInACan sealed with him]] when the Princesses defeated him, and then kept sealed by him upon his [[Recap/MyLittlePonyFriendshipIsMagicS2E1TheReturnOfHarmonyPart1 release]] to be set free as a backup plan in case he was defeated again. [[spoiler:Of course, Chrysalis has no intention of continuing to serve him.]]
* {{Franchise/Transformers}} Mosaic: [[http://transformers-mosaic.deviantart.com/art/Way-to-Fall-141127129 Gave one to Abraham Dante, in "Way to Fall."]] A man who sought Immortality and Power even at the cost of his own humanity. He made a [[DealWithTheDevil deal with Skorponok]] for that immortality.
-->"And so little by little the monster inside his soul would wake up. Little by little he would change his outer appearance to match what his soul had gotten dark with: rage, hate, and fear..."
-->"That's the Story of a man... who wasn't."
* ''FanFic/ShadowsAwakening'': [[OriginsEpisode Chapter 11]] details [[BiggerBad The Phantom]]'s origins — he was once a samurai named Kyosuke, who was the protege of the Emperor's High Shogun, but who grew unhappy with the fact that the Emperor is only ruler because of the supposed divine right of his ancestors, rather than any [[AsskickingEqualsAuthority real power]]. Because of this, when he was sent to infiltrate the Brotherhood of Shadows (the dark wizards who created the Shadowkhan), they were able to convince him to join them, becoming their leader, the Dark Champion. He then led them on a conquest of Japan, until he was [[CavalryBetrayal abandoned by Tarakudo]], and struck down by his former master. With his dying breaths, his [[ThePowerOfHate rage]] at Tarakudo's betrayal transformed his spirit into [[OurGhostsAreDifferent the Phantom]].
* The Shadow Queen's journey FromNobodyToNightmare is told in two non-consecutive chapters of ''[[Fanfic/YuGiOhTheThousandYearDoor Yu Gi Oh! The Thousand Year Door: Redux]]''. The protagonists hear the first part in [[https://www.fanfiction.net/s/8130614/36/Yu-Gi-Oh-The-Thousand-Year-Door-Redux Chapter 36]] from a descendent of a survivor of her atrocities, and the Queen herself decides to tell them the rest later, in [[https://www.fanfiction.net/s/8130614/42/Yu-Gi-Oh-The-Thousand-Year-Door-Redux Chapter 42]]. It's a long, sad, tragic story that started with a poor beggar being neglected, losing her two brothers, and ending up making a DealWithTheDevil after falling into a DespairEventHorizon.
* The MLP fic ''[[http://thejboy88.deviantart.com/gallery/42768477 Shadows]]'' provides one for [[EvilOverlord King Sombra]]. He not only UsedToBeASweetKid [[spoiler: (Celestia's, in fact)]], but he actually [[ShadowArchetype wasn't all that different from Twilight]], being a kindhearted academic with a close-knit circle of friends. However, watching his father [[spoiler: Star Swirl the Bearded]] grow old and die, he became terrified by the thought of death, and obsessed with achieving immortality. This obsession led to him driving away his friends, [[ArcWelding creating the Alicorn Amulet]] to try and boost his power to god-like levels, and ultimately his MoralEventHorizon crossing of conquering the Crystal Empire.
* In ''[[FanFic/AceCombatEquestriaChronicles Ace Combat: Wings of Unity]]'', the BigBad, Aurora Starlight, was intially a curious unicorn filly. When she heard about the alicorns and got additional information from Princess Celestia, things began to go downhill. Her attempts at gaining wings were met with Celestia's disaproval, she was banished from Equestria for life, because her experiments were perceived as dangerous. For the next 50 years, she was planning revenge against the princess she used to adore.
[[/folder]]

[[folder:Films -- Animation]]
* According to his backstory, the evil Toad from ''WesternAnimation/FlushedAway'' was once the pet toad of the Prince of England, but one day the Prince received a pet rat for his birthday and flushed the Toad down the toilet. As a result Toad actually developed a hatred against all rats and wanted to have them all drown when the sewers get flooded during a soccer game due to the audience all using the toilets all at once. Ironically, some of his henchmen are actually rats.
* In ''WesternAnimation/KungFuPanda'', we get brief glimpses of Tai Lung's when Oogway refuses to give him the Dragon Scroll. Master Shifu was partly to blame for this as well, since he never properly disciplined Tai Lung, and instead continuously praised and encouraged him, which helped lead to his FaceHeelTurn.
* Shown in a prologue in ''WesternAnimation/TheIncredibles'' on how Mr. Incredible giving Buddy, his #1 fan, the cold shoulder eventually turned him into Syndrome.
* A tie-in storybook based on Disney's ''Disney/TheLionKing'' was actually about Scar's backstory which explains not only how and why he became the series' BigBad, but also how and why he got his scar in the first place, as well as his real name.
* ''WesternAnimation/{{Megamind}}'' narrates his own start of darkness being the villain to Metro Man back when they were school kids. Metro Man was adored by their classmates, but no matter what he tried, no one liked Megamind. So, he decided, since being bad seemed to be the ONE thing he was good at, [[ThenLetMeBeEvil he would BE as bad as he could be]]!
* ''WesternAnimation/ToyStory3'' gives us a {{flashback}} of [[spoiler:Lotso-Huggin' Bear]] being accidentally abandoned in a field on a picnic, then replaced with a new model. The flashback's narrator tell us "something snapped that day."
* In ''Disney/WreckItRalph'', there was once a character named Turbo, protagonist of the racing game ''[=TurboTime=]'', who '''loved''' the attention he got from gamers when they played his game. When a newer racing game, ''Roadblasters'', came to the arcade and took the gamers' attention away from him, he [[BerserkButton didn't take it well]]. He took it '''so''' poorly, in fact, that he left his own game and entered ''Roadblasters'' in an attempt to sabotage it. He succeeded, at a price: both ''[=TurboTime=]'' and ''Roadblasters'' were deemed permanently out-of-order, unplugged and removed from the arcade. Turbo's reckless actions were so shocking that a phrase was created to describe them: "going Turbo". It's actually through an explanation of the meaning of the phrase that the aforementioned events are shown in a {{flashback}}. It turns out that [[spoiler:Turbo actually survived and went on to invade an even newer racing game by the name of ''Sugar Rush'', forcing himself into the game with a disguise and a new name: "King Candy". Unfortunately, the game already had a playable royal by the name of Vanellope von Schweetz, but he soon [[DummiedOut fixed that little issue]]. ...So, yeah, he's definitely the BigBad.]]
* Randall in ''WesternAnimation/MonstersUniversity'' starts to despise Sulley after [[spoiler: Sulley accidentally humiliates Randall in the last round of the Scare Games.]]
[[/folder]]

[[folder:Films -- Live-Action]]
* The trilogy of ''StarWars'' prequels, showing how the Empire was formed and how Anakin Skywalker became Darth Vader.
* ''Film/FreddysDeadTheFinalNightmare'' has shades of this in the flashbacks of Freddy's memories when Maggie goes inside his head.
* ''Film/TheTexasChainsawMassacreTheBeginning'' for Leatherface.
* ''Film/XMenFirstClass'':
** Magneto.
** The film depicts Mystique as an insecure young woman looking for a purpose...[[WellIntentionedExtremist And she finds it.]]
*** Taken even further in ''Film/XMenDaysOfFuturePast'', where she effectively becomes a DarkActionGirl. Xavier even states that her first deliberate murder [[spoiler: of Bolivar Trask in the original timeline]] "is when Raven became Mystique".
* The 1951 ''Film/{{Scrooge|1951}}'' explores this during the Christmas Past sequence, more so than other adaptations of ''Literature/AChristmasCarol''.
* The flashbacks in ''Film/TheGodfatherPartII'' show how Vito Corleone got to where we saw him in [[Film/TheGodfather the first movie]]. When he's a little boy in Sicily, his family is killed by the mafia, and he has to be smuggled to America to avoid the same fate. He grows up to get married and work in a grocery store, apparently not planning on a criminal career, until he loses his job to the nephew of the local mafia boss and, around the same time, is lured into his first robbery by a friend. Later, when the aforementioned boss demands a cut of the proceeds from the friends' now brisk trade in stolen goods, Vito decides to kill him instead and [[KlingonPromotion effectively replaces him]] in the neighborhood. His evolution is complete when we see him travel to Sicily to [[BestServedCold avenge his family's murder]]. All of this is a parallel to his son's ProtagonistJourneyToVillain in the present-day parts of the film.
* ''Film/IronMan3'' shows Killian's start of darkness after Tony doesn't meet him on the roof to talk about A.I.M. He looks over the edge and considers suicide, until he realises that no one even knows he's there.
* ''Film/JamesBond''
** Francisco Scaramanga of ''Film/TheManWithTheGoldenGun'' tells his to Bond while watching a kickboxing match.
-->When I was a boy, I was brought up in a circus. My only real friend was a huge, magnificent, African bull elephant. One day, his handler mistreated him and he went berserk. Bleeding, dying, he came and found me, stood on one leg, his best trick, picked me up and put me on his back. The drunken handler came along and emptied his gun into his eye. I emptied my stage pistol into his! You see, Mr. Bond, I always thought I loved animals. Then I discovered that I enjoyed killing people even more.
** Janus (aka [[spoiler: Alec Trevelyan]]) from ''Film/{{Goldeneye}}'' tells his to Bond in the statue park scene.
--->We're both orphans, James. But where your parents had the luxury of dying in a climbing accident, mine survived the British betrayal and Stalin's execution squads... but my father couldn't let himself or my mother live with the shame of it. MI6 figured I was too young to remember... and in one of life's little ironies, the son went to work for the government whose betrayal caused the father to kill himself and his wife.
[[/folder]]

[[folder:Literature]]
* ''[[Literature/TheSilenceOfTheLambs Hannibal Rising]]'' is a poorly-executed Start of darkness for Hannibal Lecter, giving him a FreudianExcuse for many of the things he's famous for, even though he explicitly stated in the first movie that there wasn't any past trauma behind his deviant behavior -- making him yet another intellectual in blatant denial.
** Rather sadly, this was an [[EnforcedTrope enforced]] case - Hannibal's creator, Thomas Harris, ''wanted'' to leave him an enigma with no real reason behind his crimes, but [[ExecutiveMeddling he was flat-out told by his publishers that if he didn't write it, they'd find someone else to do so]].
* The ''Literature/JaneEyre'' prequel, ''The Wide Sargasso Sea'' it shows the early life of a character thought of as villainous, but ultimately revealing them as well-intentioned and victimized by others.
* The ''{{Warcraft}}'' novel ''RiseOfTheHorde'', which details the fall from grace of the Eredar, along with the beginnings of the evil Horde in the first two games, [[ExactlyWhatItSaysOnTheTin as you might've guessed by the title]], as well as the aptly-named ''Literature/{{Arthas}}: Rise of the Lich King''.
* The ''StarTrekDestiny'' trilogy reveals the origins of the Borg Collective.
* A minor example in the ''StarTrekTheLostEra'' novel ''The Art of the Impossible''. Corbin Entek, a Cardassian Obsidian Order villain from a highly popular episode of ''Series/StarTrekDeepSpaceNine'', is a lowly junior probationist in this book, albeit a promising one. The novel features a sub-plot in which he settles into the Order and earns the admiration of Enabran Tain.
* The Franchise/StarWarsExpandedUniverse has several examples:
** ''OutboundFlight'' serves as a Start of Darkness of sorts for [[TheChessmaster Grand Admiral Thrawn]]. Although he isn't exactly ''evil'', it does explain why he took Palpatine's side. Eventually. Well, it introduces him to Darth Sidious and shows how perilously close he is to being exiled for his tactics. We know from the short story "Mist Encounter" that after he was exiled some Imperials found him and brought him back.
** The novel ''DarkRendezvous'' has several flashback scenes that explore Count Dooku's past and gives him a very convincing SOD backstory.
** ''TheHanSoloTrilogy'' by A.C. Crispin features a character who appeared first in ''DarkEmpire'', the comic book series set years after the novels but released years earlier. In ''Dark Empire'', readers learned that he was an old friend of Han's, and also that he was willing to throw away that friendship by leading Han into a trap just for [[OnlyInItForTheMoney the reward]]. Crispin shows us in her prequels what a good and heroic guy he used to be, and eventually what happened to change him: he was captured, [[BeingTorturedMakesYouEvil tortured]], and crippled for life.
** ''Literature/DarthPlagueis'' is this for Palpatine, Dooku, and Nute Gunray. Though unlike the other two, Palpatine was evil from the beginning, and the book merely shows how he became a Sith.
* ''[[Literature/WarriorCats Warriors]]: The Rise of Scourge''. It turns out that Scourge was, at first, just a cute little kitten with a crappy childhood. Desperate to impress the world around him, he is driven to first scare a dog away, then eventually actually ''kill'' a cat to maintain his peers' respect, which he claims his MoralEventHorizon.
* ''TabletopGame/{{Warhammer 40000}}'' novels:
** The ''Literature/BloodAngels'' short story "Blood Debt" serves as one for [[spoiler: Ramius Stele]].
** ''Thousand Sons'' serves as one (a REALLY tragic one) for [[ExactlyWhatItSaysOnTheTin the Thousand Sons]], especially for Maginus the Red. Also confirms that the [[spoiler: Blood Ravens are indeed descended from the Thousand Sons.]]
** The entire ''HorusHeresy'' is one big Start of Darkness, only made worse by the ForegoneConclusion. Good luck getting attached to people you know are going to die and/or commit a sharp FaceHeelTurn.
* ''Series/BabylonFive'' has "Deadly Relations -- Bester Ascendant".
* ''Wisdom's Daughter: The Life and Love Story of She-Who-Must-Be-Obeyed'' by Creator/HRiderHaggard details the origins of Ayesha, the BigBad of ''Literature/{{She}}''.
* In ''DeadSouls'', Chichikov and Plyushkin started out as decent people, and there's a CryForTheVillain in revealing how both of them descended into what they are now.
* In ''Literature/HartsHope'', a chapter is devoted to explaining how eventual BigBad Princess Asineth is shaped by events ranging from someone else being punished for her disobedience, accidentally causing the execution of her father's favorite mistress, and [[WhatTheHellHero being raped in public by her father's killer to cement his claim to the throne]].
* The Literature/DoctorWhoMissingAdventures novel ''The Dark Path'' tells how the Second Doctor sees his old friend Koschei become the Master, due to LoveMakesYouEvil. This may or may not be compatable with the Start of Darkness shown in "The Sound of Drums".
* VC Andrews wrote a prequel to ''Literature/FlowersInTheAttic'' called ''Garden of Shadows'' that helps explain the motivations and backstory of the EvilMatriarch Olivia Foxworth.
* Through excerpts from the novel Descarta is reading and [[spoiler: Virgil]]'s own flashbacks we see how Kalthused of ''Literature/WithinRuin'' went from hero to utterly corrupt.
* The ''TabletopGame/MagicTheGathering'' novel ''Literature/TheThran'' is this for Yawgmoth, showing him rise from an exiled doctor into becoming first dictator of Halcyon, and then the BigBad GodOfEvil he's mostly known as.
* In Literature/ASongOfIceAndFire, Catelyn Stark's memories of her [[UnluckyChildhoodFriend old friend]] Petyr Baelish are that of a sweet, [[LoveMakesYouEvil romantic kid]]. Despite the fact that she [[LikeBrotherAndSister was never interested in him that way]], his romantic idealism spurred him on to duel her betrothed Brandon Stark for her hand, which resulted in Petyr nearly dying and getting sent packing back to his own poor home [[spoiler: although that quite probably had more to do with the outcome of him being rejected and raped (whilst drunk and [[BedTrick believing himself in bed with Cat]], by her sister, [[AllLoveIsUnrequited Lysa]], resulting in her pregnancy, which their father forces her to abort.]] In the present, Petyr is a full-on MagnificentBastard and [[TheChessmaster chessmaster]], [[spoiler: in control of both the Vale and Riverlands after having manipulated, married, and murdered Lysa, and has taken on Cat's [[ReplacementGoldfish lookalike daughter]] Sansa, herself a BrokenBird, as both protegé and potential love interest.]]
* [[ByronicHero Fëanor]] of ''Literature/TheSilmarillion'' has his over the course of several years due to a combination of manipulation, jealousy and anger issues, but the single defining moment is when he lets his anger and jealousy for his brother Fingolfin get the better of him and puts his sword to Fingolfin's chest and threatens to kill him.
* ''Clariel: The Lost Abhorsen'', forthcoming prequel to the ''Literature/OldKingdom'' trilogy, is set to depict how its title character became [[spoiler: Chlorr of the Mask, an evil necromancer who served as one of the main villains of the second and third books]].

[[/folder]]

[[folder:Live-Action TV]]
* [[Series/BreakingBad Mike Ehrmantraut broke bad]] when dealing with a domestic dispute case with a routine wife beater as a beat cop. He eventually became fed up, took the husband out into the desert and threatened to kill him if he hurt his wife again. Weeks later, the man ended up killing his wife, and Mike is implied to have made good on his promise. Shortly afterwards, he was let go from the force, and his life as a career criminal began.
* Barney in the first season episode "Game Night" of ''Series/HowIMetYourMother''. We learn how he evolved from a long-haired hippie guy into the Barnacle.
* The Master gets a some of this in the ''Series/DoctorWho'' episode "The Sound of Drums". It's revealed he was driven insane during a procedure on Gallifrey of staring into the Untempered Schism, a gap in the fabric of reality which exposes the time vortex. This then expanded upon in "The End of Time", where it turns out Rassilon, Lord President of Gallifrey during the last days of the Time War, retroactively drove the Master insane on his own command to establish him as a link between Gallifrey inside the time-locked Time War and the tangible universe outside it.
* ''Series/{{Heroes}}''
** The episode "Six Months Ago" shows how Sylar first killed a man and stole his power. Two seasons later, another flashback from the same moment in ''Villains'' expands the story and shows Elle and Noah Bennet are at least partially responsible for him becoming a serial killer. [[spoiler:Especially since Elle stopped Sylar from committing suicide by hanging in the first place.]]
** The Volume 2 story arcs in feudal Japan show the Start of Darkness for [[WhoWantsToLiveForever Adam]] [[AGodAmI Monroe]], and some arcs in the axillary graphic novels show the background of characters like Thompson and Linderman.
** In Volume 4, we also get the background for Angela Petrelli as well as the beginnings of [[TheMenInBlack The Company.]]
* In season 5 of ''Series/BuffyTheVampireSlayer'', Spike gets a Start of Darkness episode called "Fool for Love".
** Then he gets another one in season 7, this time dealing with [[EvenBadMenLoveTheirMamas his relationship with his mother]].
** Anya got one in season 7, although it's revealed [[NoSocialSkills her base personality]] hasn't changed as much as you'd think.
** The books and comic books have reenacted Drusilla's Start Of Darkness at least twice. Since it involved Angelus murdering her family and torturing/raping her until she lost her mind, this is usually done to elaborate on Angelus' guilt.
** Drusilla got a flashback in "Becoming Part 2" as well as the episode "Dear Boy" on ''Series/{{Angel}}'' showing her as a human the time Angel started stalking her.
* While Series/{{Angel}} gets plenty of flashbacks on his spin-off series, the season 1 episode "The Prodigal" specifically shows his human life and eventual siring from Darla. Speaking of Darla, she gets an episode like this to herself in season 2.
* The ''Series/ColdCase'' episode "The Woods" explores the background of a SerialKiller who made his debut earlier in the season.
* In ''TheSarahConnorChronicles'', the two part episode "Today is the Day" does this for Jesse.
* The ''CriminalMinds'' episode "No Way Out Part II: The Evilution of Frank" has the team delve into the past of Frank, who had appeared in a previous episode and was described by Gideon as "the most prolific serial killer ever".
* ''Series/{{Lost}}''
** The Season 3 episode "The Man Behind the Curtain" shows how Benjamin Linus initiated the Purge and became the leader of the Hostiles/Others, though he's more of an anti-hero than a villain.
** One of the last episodes explains why the Man in Black is evil in a full-episode flashback ([[spoiler:Jacob pushed him into the heart of the island and he popped out as a smoke monster]]).
* ''{{Holocaust}}'' has this for a major plot thread with Erik Dorff, initially a man of conscience who joins the SS at the urging of his opportunistic [[LadyMacbeth wife]], is ordered to oversee a Nazi death camp and eventually slides into becoming a monster that only Heinrich Himmler could admire.
* Teen Wolf has this with "Fury" for Matt, "Visionary" for Deucalion, and "The Overlooked" for The Darach, as well as season one for Peter Hale.
* The episode "Katerina" of ''Series/TheVampireDiaries'' delves into the history of the eponymous Magnificent Bitch.
* Several non-consecutive episodes of ''XenaWarriorPrincess'' dealt with how Xena became a Warrior Princess.
** There were also episode detailing Callisto's rise.
* Each of the {{Big Bad}}s on ''{{Warehouse 13}}'' get an episode (or details spread out over several episodes) explaining how they became the villains we know them as:
** [=MacPherson=] used the Phoenix artifact to save his lover; by "dying" temporarily, he saw the afterlife, which from his point of view was nothing but darkness. He assumed this meant that there was nothing after life, and that all that matters is the now.
** H. G. Wells lost her daughter, and started seeing [[HumansAreBastards only the worst in people]]; when she was de-Bronzed in the present, she saw things had only gotten worse [[spoiler: and was pushed straight into OmnicidalManiac territory]].
** Walter Sykes was [[TheCorruption corrupted]] as a child by an artifact that let him walk; when it was confiscated by Warehouse agents (specifically, [[spoiler: Pete's mom]]), he became obsessed with getting it back and getting revenge on the Warehouse for taking it away.
** [[spoiler: Season 4 turns out to be one long SOD for Artie as his EnemyWithin (manifesting as a hallucination of [[KnightTemplar Brother Adrian]]) slowly consumes him.]]
* Rumplestiltskin in ''Series/OnceUponATime'': In order to prevent his son to be drafted into the ogre war, he gained magic powers by killing the Dark One.
** "The Stable Boy" does this for Regina. Her ambitious and cold-blooded mother wanted her to marry up, but she was in love with a stable boy. When Snow White, then an innocent child, tried to help Regina by letting the ambitious mama know her stepmother-to-be was with the stable boy... Well, let's just say ''someone's'' True Love ended up dead, and Snow White [[NiceJobBreakingItHero ended up on the wrong end of a vendetta.]]
** "The Miller's Daughter" showed how Cora became who she was. When she was a young woman, [[spoiler: she was tripped by an immature Eva (Snow White's mother before she married Snow's father) who claimed Cora hurt her.]] The King of the land forced Cora to apologize on her knees or he wouldn't pay her for the flour. She would later use the emotions she felt here to channel her magic to spin gold.
* ''{{Smallville}}'' is this for Lex Luthor. To be more accurate, [[spoiler:season five, ''Lexmas'']]. By Season 7 he's become the megalomaniac we all know.
* Morgana Pendragon gets a similar treatment in ''Series/{{Merlin}}'' though in terms of personality, she's more Magneto than Lex Luthor. By Season Three, she's ruthless and cold, by Season Four, she shows remorse, and becomes more human, though still a WellIntentionedExtremist.
** Well, the above is probably the intent of the series, realistically all the AccordingToTheWriter and the difficulty of turning a one-scene villain from the myth into a six-season character that had to survive to the end, it plays more like she's just schizophrenic and her evil personality turns up whenever a coin comes up tails somewhere in the kingdom. Her intentions would have to be coherent for her to be a well-intentioned anything.
** Mordred counts as well. He's been in a total of three episodes [[spoiler: although he is returning for series 5]], and he's already got a FreudianExcuse, budding [[TheSociopath sociopathic]] tendencies, and become ''way'' too willing to kill people for a child who grew up with pacifists and can't be more than 9.
* ''[[SpartacusBloodAndSand Spartacus: Gods of the Arena]]'' shows how Batiatus and Lucretia's [[PeerPressureMakesYouEvil ambitions led them to compromise their morals]] and become the utterly corrupt {{Manipulative Bastard}}s they are in ''Blood and Sand.''
* Season 1 of ''Series/{{Carnivale}}'' delves heavily into Brother Justin's Start Of Darkness,as he develops from a compassionate and deeply moral laypriest into (at the very least) an unrepentant demon. It doesn't help that [[spoiler: this was his bloodline]] and [[spoiler: his sister murdered a bunch of orphans to engineer a personal tragedy for him]].
* ''Series/PersonOfInterest''
** For Carl Elias, it was his Mafia boss father killing his mother, and then trying to kill Elias.
** For Samantha Groves (super-hacker "Root"), it was when her childhood friend was murdered and an adult she respected covered up for the killer. One of her first forays into hacking was done to visit LaserGuidedKarma on the killer.
** For Peter Collier, it was having his brother detained without charges and DrivenToSuicide because a man he knew from his Alcoholics Anonymous meetings resembled a terrorist recruiter, followed by the officials responsible never getting punished.
* ''Wentworth''
** In a series that acts as a reimagining/prequel to a show about a ruthless women's prison and the top dog that rules it, this is almost inevitable, but in Season 2 Episode 1 [[spoiler: we finally see it. Bea overcomes her drug dependency, but takes a final sedative so she can visit her murdered daughter, Debbie, one last time in a hallucination. She says her goodbyes and assures Debbie that she has a new purpose now. Then she stares down Debbie's murderer as the warm light of the idyllic scene is replaced with the cold green-gray of prison and says, [[BadassBoast "I'm gonna kill the fucker."]]]]

[[/folder]]

[[folder:Music]]
* DoctorSteel's ''[[http://www.youtube.com/watch?v=XvOJHyDypf8 Lament for a Toy Factory]]''.
[[/folder]]

[[folder:Multiple Media]]
* The ''{{Bionicle}}'' web-serial ''Mutran Chronicles'' and a scene from the book ''Swamp of Secrets'' reveal just why the formerly benevolent [[BrotherhoodOfEvil Brotherhood of Makuta]] turned against the Matoran Universe -- it was because the peoples of the universe all attributed their efforts to preserve the balance of things to Mata Nui, and shunned them for being affiliated with the element of shadow. They got fed up with this. The comic ''Rise and Fall of the Skrall'' also details why the titular race wanted to overrun the desert region of Bara Magna along with its locals -- they were driven out of their home-realm by robot assassins, and needed the space to fight back. Although it's to be assumed that being mean has always been their way.

[[/folder]]

[[folder:ProfessionalWrestling]]
* There have been several in-character ones over the years. It can be argued that Wrestling/RandyOrton's slow descent from the suave Legend Killer to the sadistic Viper was a result of his ousting from Wrestling/{{Evolution}}, something he never got over. Evolution played a major part in Randy's character and actions, being the reason for his hatred for Wrestling/TripleH, extending all the way to 2009, four years after the stable had fully dissolved, and yet at the same time a blueprint for Randy's own power stable Legacy. It's also pointed to as the main reason why Randy had gone kayfabe-insane in 2009. The event had such an effect on him that one could argue that it defines his ''entire'' career. Only recently has he managed to get over it.

[[/folder]]

[[folder:Tabletop Games]]
* The NewWorldOfDarkness games all have a mechanic that encourages this trope for players: as the players sin or make immoral or counterproductive choices, they "degenerate", making future choices of slightly greater depravity and further degeneration easier and more likely. Each degeneration can also give a character a minor derangement such as a phobia or narcissistic tendencies, which can force further sins even if the player doesn't want to do so.
** Fits this trope because at the bottom of the scale the player becomes so irrationally self-centered and evil that they cannot be played and become an NPC. What kind of monster depends on the game: for mortals, you become a SerialKiller, werewolves become a movie-style wolf-man that hunts humans for fun, changelings become completely unable to tell imagination from reality, vampires become ravening blood-crazed beasts, and mages turn everything in their area of effect into a CthulhuMythos story.
[[/folder]]

[[folder:Video Games]]
* ''VideoGame/MetalGearSolid3SnakeEater'' featured Naked Snake, who would later become Big Boss from the very first ''Metal Gear'', in his US military operative days. Instead of being the traditional [[CardCarryingVillain Bond Villain archetype]] he'd been in the previous game - or even the wise but guilty character his son was - he was a highly energetic, lovable dork. While [[SuperSoldier certainly capable of wiping out enemies with the best of them]], Big Boss seemed to prefer spending his time playfully messing with the heads of his medic and tech. [[spoiler:Unfortunately, being forced to kill your own {{Mentor}} by an AncientConspiracy so that said conspiracy can [[TakeOverTheWorld take over first your country and then the world]] can change and disillusion a man.]]
** ''VideoGame/MetalGearSolidPortableOps'' takes this further, showing him continue to be disillusioned, and marking his transition from a lone soldier to a competent and respected leader.
** Where ''Snake Eater'' and ''Portable Ops'' planted the seeds, the ending of ''VideoGame/MetalGearSolidPeaceWalker'' begins sprouting Big Boss' FaceHeelTurn.
** And finally, Big Boss' FaceHeelTurn will be completely cemented with ''VideoGame/MetalGearSolidGroundZeroes'', and the MoralEventHorizon will be crossed on ''VideoGame/MetalGearSolidVThePhantomPain''.
** The Jetstream DLC of ''Videogame/MetalGearRisingRevengeance'' shows how [[TheRival "Jetstream" Sam Rodrigues]] ended up involved with Desperado.
* ''VideoGame/SuperRobotWars Original Generation Gaiden'' features the Start of Darkness of one of MX's BigBad Albero Esto. It was only mentioned several times in MX, but in OG Gaiden, it's... rather full-blown and detailed.
** In Alpha Gaiden, Char's FaceHeelTurn (since CharsCounterattack is part of Alpha 2) makes even more sense then it's UC Gundam verse reasons. During the course of the plot, he watches humanity keeping picking the TooDumbToLive options and the horrifying results, and this disillusions and pisses him off enough to decide a ColonyDrop is actually a good idea.
* ''VideoGame/SengokuBasara 2 Heroes'' features a Gaiden story for Maeda Keiji, which in fact was a Start of Darkness for a villain in the actual game, Toyotomi Hideyoshi. Hideyoshi starts out as a normal man, joining Keiji in pranks here and there, until he encounters [[MagnificentBastard Matsunaga Hisahide]], who proceeds to humiliate him, and this causes him to become drunk with power, leaving Keiji and doing a lot of atrocities later on.
* The ''Franchise/MassEffect'' novel ''[[Literature/MassEffectRevelation Revelation]]'' serves as a Start of Darkness for Saren, showing how he came to be the villain in the videogame....though in the novel itself, he's already an ''extreme'' KnightTemplar.
** The comic ''Mass Effect: Evolution'' is one for The Illusive Man and Cerberus.
* About one third of ''CrisisCore'' is spent on telling us how Sephiroth became the MagnificentBastard and OneWingedAngel he is in ''VideoGame/FinalFantasyVII''. Including remaking Cloud's flashback scenes from the original game to the actual ''moment'' he snapped, also a Start Of Darkness in their own right. This took advantage of advances in animation and allowed for Cloud's serious amnesia problem. (Also the EpilepticTrees spawned when he had ''dialogue'' right for a scene he ''was not actually present for.'' Some fans believe his delusion of Zack-ness was largely caused by some kind of Hojo-induced memory transfer.)
** The game proved that he didn't suffer a sudden sanity loss, but rather more of a long line of betrayals that started as early as Gast's death and ended with the very facts of his own existence, which overall is both more believable (even allowing for Jenova's clear ability to mess with his brain) and more tragic. Due to CrisisCore we know that he had lost absolutely everything by the time this happened.
** His Start Of Darkness could be pinned at conception, at the moment he broke, or just described as 'his whole damn life.' The man was born one of Hojo's experiments. Their suffering has been unquestioned more or less since Hojo was introduced. Though he still had just enough innocence left during that fateful practice duel that events afterward could almost be labeled 'BreakTheCutie'.
* Prince Luca Blight from Suikoden II had his after his family was ambushed by bandits in one of their official travels. He and his father managed to escape, but his mother wasn't so lucky. Luca wanted to go back for her but his father said that he couldn't risk his life as the King. His mother was rescued shortly after, but she didn't return to the castle. Several months later, Luca managed to find out where she was and quickly escaped from the castle in order to meet her. He had a arduous journey, and a man took his horse in exchange for a pear and some water (Luca didn't want to eat the wild berries or drink the muddy water he found in the way). Upon finally meeting his mother, she started to scream and rip her hair out when Luca came close. One of their aids explained that she was brutally raped by the bandits and got pregnant, as well as going completely insane and unable to stand near men. Luca then snapped. He went back to the castle, but not before meeting the man who took his horse, who he murdered with joy. He was also lucky enough to find a small village along the way, and found that the bandits, as well as his mother's rapist, were sheltered in a house there. He stormed inside the hut and caught everyone off-guard, murdering everyone. When he found the rapist, he tortured and killed him gruesomely. When he returned to the castle, two things were permanently scarred on his mind: the disgust for people and the pleasure he got when killing. Thus, Luca Blight, who causes a war for the sole reason of having an excuse to kill people by the thousands.
* ''VideoGame/TheLegendOfZeldaOcarinaOfTime'' is the Start of Darkness for Ganondorf, explaining how he became the King of Evil Ganon.
** In ''VideoGame/TheLegendOfZeldaTheWindWaker'', [[spoiler: before the final duel with him]], Ganondorf's backstory was expanded by revealing his motives for conquering Hyrule in the previous game.
** Likewise, ''VideoGame/TheLegendOfZeldaTheMinishCap'' is the Start of Darkness for Vaati, and explains his origins as a Minish sorcerer's apprentice.
** ''VideoGame/TheLegendOfZeldaSkywardSword'' serves to show a Start of Darkness for the series, [[spoiler:seeing as every figure of evil that appears in the Zelda universe, Ganon or otherwise, is a result of Demise's curse incarnate.]]
* ''Kagetsu Tohya'' fleshes out [[{{Tsukihime}} Michael Roa Valdamjong's]] start of darkness with the Crimson Moon and Drinking, Dreaming Moon scenarios. Roa actually wanted to achieve immortality because he fell in love with Arcueid and wanted to be with her for eternity, but mistook that feeling for hatred and thought he wanted to torment her for eternity.
** [[KaraNoKyoukai Araya]] wants to take over Ryougi's body because he wants to reach Akasha, so all the meaningless deaths would at least have a reason and cease to be meaningless. ect.
* In ''LiveALive'', the hidden [[spoiler:Medieval]] Chapter explains just who and what "Odio" is, and what made him into the demon of hatred influencing the various end bosses. [[spoiler:It starts the young, heroic, KnightInShiningArmor Oersted on a fairly formula "Save the princess from a demon" plot, but... well, to say it all goes to hell about halfway through would be an understatement. By chapter's end, everyone in the kingdom believes Oersted to be the ''real'' demon (over something that was an accident, not that they saw that part of it), everyone who believed in him is either dead, or being "protected" from him, his best friend is revealed to be the one who ruined his life, and the princess declares her own hatred for him after he duels said traitorous friend to the death, and then ''commits suicide''. Oersted is left with ''absolutely nothing''. He then proceeds to just plain ''snap'', and decides that if the world is so insistent that he is a demon, [[ThenLetMeBeEvil then a demon is exactly what he will be.]]]]
* ''VideoGame/DragonFable''[='=]s Fire War is a Start Of Darkness for Drakonnan. [[spoiler:Once Yulgar's apprentice, Konnan called upon the hero to stop the rampage of the red dragon Akriloth upon his home village. But despite the hero's best efforts and the powers of the hero's recently acquired dragon, [[HopelessBossFight they were no match for Akriloth and the power of the Fire Orb]]. Akriloth, instead of finishing the hero, sadistically [[ForcedToWatch made them watch]] as he burned the village to the ground, killing Konnan's family. Konnan [[FailureToSaveMurder blamed the hero for failing to save them]] and when the evil pyromancer Xan got his hooks into him, this would turn into a desire for revenge that would soon threaten the entire land of Lore]].
* InThe1stDegree has James Tobin charged with grand theft and murder. There are indications in the interrogation tapes that the chain of events leading up to the events in the game go back to when Tobin and his wife Helen divorced. He apparently took it hard and just went on a steady downward spiral after that.
* ''BatenKaitos Origins'' shows how Geldoblame came to be in control of TheEmpire, and how he went from Verus' prissy YesMan to a megalomaniacal EvilOverlord.
* As seen in a flashback, the death of Sophia in ''VideoGame/{{Xenogears}}'' was the Start Of Darkness for Krelian ''and'' Grahf.
* ''VideoGame/ResidentEvilTheDarksideChronicles'' acted as the Start Of Darkness for [[VideoGame/ResidentEvil4 Jack Krauser]].
* ''KingdomHeartsDreamDropDistance'' gives us the Start Of Darkness for series BigBad Xehanort. What drove this man down his path of villainy? [[spoiler: His [[TheHeartless Heartless]] went back in time and showed his younger self all of the evil acts he would do, even bringing him to the future to help them out. Even though he would forget what he saw and do, the actions he would take are now engraved in his heart. Xehanort isn't just happy messing around with the heroes- even his youth is fair game!]]
* In ''VideoGame/InjusticeGodsAmongUs'', we learn that Superman starts his takeover of the world after the Joker tricks Supes into kill Lois and his unborn child, leading to the hidden Dead Man's Switch in her to ''activate a nuke and blow up Metropolis''.
* In ''Ravenmark Scourge Of Estellion'', [[spoiler:Livia Cassianus]] finds out that the late Emperor Sergius Corvius has always intended for [[spoiler:her]] to inherit the Obsidian Perch (i.e. the throne of the Empire of Estellion). Before that, [[spoiler:Livia]] falls in love with young [[spoiler:Calius Septim]]. In the final cutscene, [[spoiler:Calius]] gives [[spoiler:his]] life to save [[spoiler:Livia]] from the BigBad pulling a TakingYouWithMe. [[spoiler:Livia her]]self is scarred by the flamesoul explosion. At [[spoiler:Calius]]'s grave, [[spoiler:Livia]] vows to remake the Empire into something new, claiming that traitors must be rooted out, and the blood of the fallen must be repaid. The description of the sequel ''Ravenmark: Mercenaries'' claims that six years have passed since then, and that the land is still reeling from the rule of the "Scarlet [[spoiler:Empress]]".
* ''VideoGame/CastlevaniaLamentOfInnocence'' is the origin of Dracula's eternal war with the Belmonts.
* ''Videogame/BorderlandsThePreSequel'' deals with Handsome Jack's rise to power and how he went from someone with legitimately heroic aspirations to the power-hungry and delusional villain of ''Videogame/{{Borderlands 2}}''.
[[/folder]]

[[folder:Visual Novels]]
* ''FateZero'' is mostly a retelling of the Fourth Grail War, making it the prequel of ''VisualNovel/FateStayNight.'' In it, Kotomine is still more or less a good guy, though all his mental issues are still present. While the war is going on and Servants are going down, Gilgamesh is needling Kotomine towards realizing what he is and descending into villainy.
* About one-third of ''HigurashiNoNakuKoroNiKai'' is spent giving [[spoiler:Nurse Takano]] one of these.
** Shion gets one herself during the Eye Opening chapter (takes about 2 episodes in the anime, culminating with the "distinguishment" incident). The events happen in every arc (having taken place one year before the story begins, but whether the events "detonate" depends on the arc.
[[/folder]]

[[folder:Web Comics]]
* In ''TheInexplicableAdventuresOfBob'', Fructose Riboflavin has been the greatest criminal in the Nemesite Empire for the better part of two thousand years. But he UsedToBeASweetKid. [[http://bobadventures.comicgenesis.com/d/20100828.html Then his dad died...]]
* ''{{MAG ISA}}'' -- [[http://mag-isa.thecomicseries.com/comics/pl/119656 The villains]] in this comic had miserable lives before they became villains.
* The TropeNamer -- admittedly more recent than most of the other examples here, but it's still a pretty cool title -- is ''Start of Darkness'', prequel to ''Webcomic/TheOrderOfTheStick'' detailing EvilOverlord Xykon and his [[TheDragon Dragon]] Redcloak's past. Xykon, unlike most, is astonishingly evil from the get-go. We get to see him become ''more'' evil... but more importantly, a lot more ''competent''. [[AntiVillain Redcloak is a whole other story]].
** The comic's author and illustrator, Rich Burlew, said in the Introduction that the greatest challenge of ''Start of Darkness'' was to tell Xykon's backstory without making him even slightly sympathetic. He solves this problem by making Xykon's every appearance push him farther beyond the MoralEventHorizon.
--> '''''Burlew''''': ... [Xykon]'s completely and wholly unapologetically evil, but more to the point, he's kind of a [[EvilIsPetty dick]].
** The very first page of the book might have been teasing at it: Xykon is shown as someone who might come off as sympathetic for the first three or so panels, but revealed to be already evil before the page is over -- at the age of ''four''. And yet, Burlew does give him one simple human, if not quite redeeming, quality that makes his final descent, if not sympathetic, at least understandable. After being turned into an undead creature, he loses his ability to enjoy simple pleasures such as the taste of coffee. [[spoiler:And then brutally murders the diner waitress because of it.]]
** Burlew makes a point of not giving away Belkar's backstory in ''On the Origins of [=PCs=]'' (and the Belkar backstory comic for Kickstarter donors) for similar reasons, wanting the character to remain completely, unapologetically and unmistakably evil. Although, also to keep him funny. Evil isn't funny when it has a tragic backstory, just pitiable. Belkar ''does'' end up revealing a sob story in his childhood in the main comic... [[SubvertedTrope Entirely made up, it turns out, spun in order to gain roleplaying XP.]]
* In ''{{Sinfest}}'', [[http://www.sinfest.net/archive_page.php?comicID=4352 we get Baby Blue's unhappy past]]. (We ''see'' nothing of why she got those F's.)
* In Act 6 of ''Homestuck'' we learn [[BigBad Lord English's]] origin. [[spoiler: He was a boy called Caliborn who dropped himself in a "[[{{Unwinnable}} dead]]" session of Sburb (the AbsurdlyHighStakesGame the characters are playing) than slowly worked to become more and more powerful until he ultimately became a full-blown EldritchAbomination. Also subverted in that we learn he was a scumbag even before he became Lord English. If anything he simply transformed himself from a HarmlessVillain into TheJuggernaut.]]
* The flashback chapters of ''[[Webcomic/EvilPlan Evil Plan]]'' show how Stanley turned from an idealistic inventor into Urbane City's first super villain. [[spoiler: He found out his accountants were selling his inventions to super villains, he gained telekenesis via a self-experiment and accidentally killed his best friend trying to recreate it. The final scraps of his spirit crushed by trying to earn an honest buck as a bank teller, from there on he turned his company into a legitimate front, started building super gadgets, hired some minions and an engineer, opening the doors to the main story.]]

[[/folder]]

[[folder:Web Original]]
* ''WebVideo/TheSpoonyExperiment'' spoofs this in its April Fools Day review of the original ''FinalFantasy''. The Spoony One was driven insane trying to comprehend the game's time travel plot and became determined to invent his own method of time travel to stop the series from being made, ultimately causing his own time paradox by his future self appearing and presenting him with the technology fully formed. Along with a rather neat bit of acting, with Noah making a seamless transition from Spoony to Insano before our eyes.
* The version two finale of ''{{Mega64}}'' reveals how Dr. Poque became the MadScientist he is today.
* ''DoctorHorriblesSingAlongBlog'' has several {{prequel}} comics which describe how and why Dr. Horrible decided to try to become a villain in the first place. The show itself is a ProtagonistJourneyToVillain.
* ''SuperMarioBrosZ'' features a prologue where Metal Sonic becomes the deadly Mecha Sonic... and proceeds to destroy all of Mobius and kill all of Sonic's friends.
* [[http://parahumans.wordpress.com/2013/03/19/interlude-19/ Interlude 19]] of ''Literature/{{Worm}}'' follows [[spoiler:Emma Barnes]] transition from an ordinary high school student to [[spoiler:a ruthless bully determined to destroy Taylor's life]].
** The first eight arcs of the story can be considered one for Taylor.
[[/folder]]

[[folder:Western Animation]]
* The Dr. Robotnik of ''AdventuresOfSonicTheHedgehog'' has his origin told in the episode "Best Hedgehog" as a high school student expelled because he tried to kill a romantic rival with a robotic snake to woo a girl he liked. He made sure that rival was his first prisoner.
* In the episode [[WhamEpisode "Holly Jolly Secrets Part II"]] of ''WesternAnimation/AdventureTime'', we learn the Ice King's [[CerebusRetcon start]]. [[spoiler: [[WasOnceAMan He used to be a human named Simon]] [[Really700YearsOld from before]] [[ApocalypseHow The Great Mushroom War]] who bought a crown while a on trip with his fiancee Betty, whom he called "Princess." When he put on the crown he blacked out and when he came to his fiancee was disgusted and left him. Throughout the video he made you see him slowly morphing into his current form, wishing that whoever finds it to watch over him until he can figure out how to break the curse.]] It's ''really'' hard not to [[CryForTheDevil feel sorry for the]] [[SympathyForTheDevil guy after that]].
** The episode "Princess Cookie" was an episode all about this. Baby-Snaps the cookie is seen taking hostages and trying to steal the crown of Princess Bubblegum. Then, we learn of his past: he was an orphan living in a terrible orphanage, and one day, Princess Bubblegum showed up to read to the kids and cheer them up. The princess put Baby-Snaps on her lap and asked him what he wanted to be when he grew up. He jollily said: "I want to be a princess like YOU!" And the princess giggled innocently. That was the start of darkness for poor Baby-Snaps, who went on to threaten people with violence, take hostages, and attempt suicide, and end up in a mental hospital.
* ''WesternAnimation/AvatarTheLastAirbender'' has one of these. "The Storm", aside from telling how Aang ended up frozen in an iceberg, gives us how Zuko got his scar and banishment; [[spoiler: He spoke out against a general who believed WeHaveReserves, but because it wasn't his place to speak out, he had shown disrespect, and the Fire Lord declared a duel to resolve the matter. Zuko accepted, thinking he'd fight the general, but because it happened in the Fire Lord's war room, it was the ''Fire Lord'' he'd disrespected. Zuko couldn't fight his father, and begged forgiveness. Instead, he got a fireball to the face and an exile that would not be lifted until he found the Avatar, considered a SnipeHunt at the time.]]
* ''WesternAnimation/TheBatman'''s episode "Riddler's Revenge", depicting Edward Nygma's gradual transformation from geeky, unappreciated kid to murderous costumed criminal.
* ''WesternAnimation/BatmanTheAnimatedSeries''
** There is such an episode with the Riddler, wherein he creates a computer game that makes millions but is then fired by his publisher so that, as according to his contract with them, he doesn't get anything from it. And so becomes the Riddler in his attempt to punish his old boss. Notable in that this is one of the few episodes where the Villain of the Week [[spoiler: escapes, unharmed and untouched. He was never there to be caught. At the ending, where the wealthy businessman is headed to bed. Shaking in terror all the way, he locks the multiple locks on his door, climbs into bed with a double-barreled shotgun, and cringes in paranoia.]]
** The show is also credited with Mr. Freeze's backstory, who up to that point was just a cold-themed villain who turned up occasionally. The cartoon turned him into an AntiVillain [[TheWoobie Woobie]].
** Temple Fugate, a ScheduleFanatic, decided to take a break from that schedule at the suggestion of then-Counselor Hill and [[DisasterDominoes things went horribly wrong]], costing him a court case. Temple snapped and vowed revenge on Hill, now Gotham's mayor, becoming the episode's titular villain, the Clock King. He orchestrates a smear campaign against Mayor Hill as a prelude to kidnapping him and putting him in a DeathTrap.
*** Temple Fugate’s case is a bit of a DeconstructiveParody of this trope, Temple had NoSocialSkills and was a BadBoss long before the fateful day he took Hill’s advice. Even when confronted with the fact that Hill meant him no harm, Temple ''reconstructs'' this trope when he refuses to admit he's taken his obsession too far, being a ScheduleFanatic, ''being punctual is the only thing he cares for.''
--> '''Batman:''' ''Give it up, Fugate! Hill committed no crime against you!''
--> '''Clock King:''' ''[[BlueAndOrangeMorality He did worse!]] [[HarmonyVersusDiscipline He made me late!]]''
** The tie-in comic book for the series described (but did not show) one for Arnold Wesker, a.k.a. The Ventriloquist. The Ventriloquist tells Batman that he was actually born into a mob family and was encouraged by his mother not to allow himself to drift into a life of crime like the rest of the family had done. Arnold promised her he'd do this...but then his mother was killed one night by a bullet meant for his father, and [[EvenBadMenLoveTheirMamas Arnold felt that he had to avenge her]]. Even after becoming a gangster, he still kept a framed photo of his mother on his person at all times - until Scarface, in a fit of jealousy (because the Ventriloquist had been keeping company with other puppets in an attempt to distance himself from Scarface), [[KickTheDog tore up the photo]], causing Arnold Wesker's mind to snap for good.
* ''TheBoondocks'' episode "The Color Ruckus" shows the events in the life of Uncle Ruckus (no relation) that lead him to becoming a BoomerangBigot.
* In ''WesternAnimation/DarkwingDuck'', an episode is dedicated to the origin story of [[MeaningfulName Reginald Bushroot]], and how he became a villain.
* In ''TheFairlyOddparents'' episode "The Secret Orgin of Denzel Crocker," it is explained [[ExactlyWhatItSaysOnTheTin how Crocker became obsessed with fairies]] and why he's so bitter toward his students and life.
* The main purpose of the four-part ''WesternAnimation/{{Gargoyles}}'' episode "City of Stone" is to provide a framing story for one of these for [[WoobieDestroyerOfWorlds Demona]] and [[AntiVillain Macbeth]].
* Skeletor got one in ''WesternAnimation/HeManAndTheMastersOfTheUniverse2002''. Turns out he was a powerful wizard trained by Hordak who wasen't ''completely'' bad (or at least not crazy). Then his face got flash fried off. After seeing that he has a skull for a face now, he completely lost it. The scene where his sanity finally snaps can scare someone as he starts laughing into the sky like the god damned Joker.
* ''PowerpuffGirls'': Mojo Jojo's origin was intinally revealed in the episode "Mr. Mojo's Rising". Mojo's telling of the origin paints him as someone who might come off as sympathetic but Utonium reveals that Mojo was just as unsympathetic when he was Jojo. In fact, Mojo may actually be ''more'' likable and sympathetic as a supervillain than he ever was when he was just a normal monkey.
* While ''SamuraiJack'''s first episode explains the basic premise behind Aku, the episode "The Birth of Evil" tells his exact origins as a castaway shred of an UltimateEvil which the Gods fought among the stars.
* The ''TransformersAnimated'' episode "Along Came A Spider", where we find that Blackarachnia's hatred against Autobots began when Optimus Prime and his friend [[{{Jerkass}} Sentinel]] accidentally left her behind on an alien planet inhabited by spiders. While still inside the caves, Blackarachnia is accidentally mutated into a technorganic spider causing her to join the Decepticons as revenge for Optimus and Sentinel's betrayal.
* ''WesternAnimation/TheVentureBrothers'' offers a Start of Darkness for Phantom Limb in "The Invisible Hand of Fate." At one time he was a MadScientist in the dotty/well meaning sense, and chivalrous enough to turn down future-Mrs-the-Monarch's sex-for-grades proposition. Long story short, both he and Billy Quizboy were victims in a GambitPileup.
* The ''WesternAnimation/{{Wakfu}}'' special episode "Noximilien" shows how Nox, the BigBad of the main series' first season, became such a WoobieDestroyerOfWorlds. Essentially, the discovery of the Eliacube -- an extremely powerful AmplifierArtifact (and, unfortunately, ArtifactOfDoom) -- and Noximilien's subsequent obsession over it led him to neglect his family, which resulted in their loss. [[FreakOut He did not take this well]]. [[DespairEventHorizon At all]].
* Nerissa of ''WesternAnimation/{{WITCH}}'' gets one for both her comic and cartoon selves, both the same: a leader of her generation's Guardians, the Oracle feared she was becoming too attached to the Heart of Candracar and gave it to her friend Cassidy. When Nerissa demanded it back and Cassidy refused, Nerissa slew her in misguided rage.
* The ''MoralOrel'' episode "Passing" for Clay Puppington. We see him as a child, when he discovers that [[spoiler:his mother miscarried ten times before he was born]], he becomes upset and [[spoiler:briefly fakes his own death]] which causes [[spoiler:his mother to have a heart attack and die]]. This puts him at a distance with his father, who Clay [[AttentionWhore intentionally tries to provoke into hitting him so he'll be "worth it."]]
* "The Last Tough Customer" on ''WesternAnimation/{{Arthur}}'' shows Molly's in TheTeaser: when she was in maybe kindergarten or first grade, a couple of older kids teased her about her poufy hair. She took out her hairbands, letting her hair fall across her eyes, and became a bully.
* The ''WesternAnimation/{{Wakfu}}'' special "The Legend of Goultard" reveals how Goultard became a demonic berserker in the game. He was originally a brave and mighty hero who had a good life with a wife and three children. Then a villain named Katar kidnapped them to lure Goultard into a fight. Goultard tracks him down and is horrified when he discovers that Katar has already murdered his entire family. After a brutal NoHoldsBarredBeatdown, the defeated Katar explains that he did this to free himself from the demon inside him by presenting it with a tastier target. The demon is drawn to Goultard's hate and fury and possesses him. Goultard finishes off Katar and eventually becomes an immortal demonic warrior who rules over a realm of madness and horror. [[spoiler:Though in the series proper, he is eventually freed of the demon but retains the immortality and becomes Sadlygrove's mentor.]]
[[/folder]]

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