Start of Darkness



""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?""

- Heroes

Nobody is born evil (well, except maybe the Enfant Terrible). Something usually happened to push a villain down the path to villainy. And hey, mightn't that make an interesting story?

Thus, we have the Start of Darkness, a Prequel Dark and Troubled Past where we find out how the main antagonist from the original story got to that point.

This, naturally, is especially common with Fallen Heroes, who usually get a Downer Ending where they lose faith in themselves and/or humanity. This will be especially poignant if they Used to Be A Sweet Kid (see also: Freudian Excuse).

Keep in mind that the reasons 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 Foregone Conclusion, often ending in The Bad Guy Wins or Pyrrhic Villainy; many characters are Doomed By Canon, which may require a full Kill Em All to explain why they don't show up in the original work. May include a Bloodbath Villain Origin to signal the first emergence of the character's villianous side.

Badly executed, this can be a part of a Badass Decay.

Please note that this is about prequels and flashbacks that show a major villain's reasons for turning evil. If this is the subject of the main plot, you're watching a Protagonist Journey to Villain.

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

Anime & Manga

 * In Yu Yu Hakusho, the Big Bad 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
 * Mazinger Z: 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, he... flipped out and 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 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 Big Bad.
 * The 8th and final Parallel Works video for Tengen Toppa Gurren Lagann is one of these for.
 * "Two Father's Little Soldier Girls", the 21st episode of Black Lagoon contains a number of flashbacks to Balalaika's past detailing her childhood, service in Afghanistan, disillusionment with society and rise to power in Hotel Moscow.
 * Axis Powers Hetalia
 * "Hey, Lithuania, we don't want children that can't play nice, right?"
 * Russia mentions all he's endured over the centuries. This could be taken as his Despair Event Horizon, when he simply couldn't take more.
 * Almost every Rave Master 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 Rah Xephon presents the back-story of Makoto Isshiki, an Evil Albino who is a cold-hearted seducer and major jerk to pretty much 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 what he really was, and his flashback ends with him getting an Important Haircut and taking on his nasty personality.
 * One Piece 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.
 * One episode in the second season of Ghost in The Shell Stand Alone Complex focuses entirely on Kuzes' past, showing what motivated him to fight on the behalf of the people, even against the state.
 * Ga Rei Zero is explicitly stated to be the Start of Darkness of Yomi. Judging from what happen in the manga, this might also qualify as Kagura's Start of Darkness.
 * Elfen Lied. Sure, brats. Go ahead and beat to death the puppy of the shy, emotionally-repressed pink-haired girl with horns and force her to watch -- she can't hurt you.
 * Naruto has done this with many antagonists so far.
 * During his brush with Complete Monster status, Gaara's horrific childhood was touched on, showing how the betrayal of Yashimaru transformed him from an attention-starved waif to serial killer.
 * When the manga briefly touched on his past, while the anime expounded on it. His 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.
 * verged on Cosmic Plaything with how ludicrously over-the-top his suffering was as a child. Eventually,.
 * was imprisioned and punished for failing to kill the First Hokage. As a result
 * The flashback arc in both incarnations of Trigun seems at first to be the background for the highly mysterious lead, but it's even more about the Start of Darkness for the Big Bad, his Evil Twin. In the anime version, the kid was always somewhat touched in the head, and one abusive crewman, combined with the awareness that the human race destroyed the Earth and are now looking for a new planet, push his pragmatism into Kill All Humans territory. In the manga...he has much better reason.
 * Hell, his manga reason made Vash try to kill himself twice and laugh hysterically when he thought he'd accidentally killed Rem! And manga Knives Used to Be A Sweet Kid--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 Omnicidal Maniac 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 asked his name! Weirdest Crowning Moment of Heartwarming 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  and then later he was
 * Anime Wolfwood also gets one. Manga Wolfwood just gets back story snippets. But because the anime is Lighter and Fluffier, Wolfwood's philosophical position has a lot less pull there, so he needs a more clear-cut 'reason' to think the way he does.
 * Puella Magi Madoka Magica episodes 3-8 count as one for, of all people.
 * Romeo X Juliet practically drops it line for line with the episode "Darkness: The Origin", which gives Prince Montague a somewhat run-of-the-mill Freudian Excuse.
 * 2007 adaptation of Skull Man features one for
 * Episode 11 of Last Exile Fam the Silver Wing shows the event that ended up shaping Luscinia Hafez into the series' Big Bad.
 * Berserk Golden Age Arc serves as one for, villain who was previously seen once, right before the arc started.
 * Pokémon: The Origin of Mewtwo is this to... ...guess who.
 * Fate Zero is one for Kotomine Kirei.

Comics -- Books

 * The Batman Graphic Novel The Killing Joke is a Start of Darkness story for the Joker. Just one of several, in fact.
 * Pretty much a large portion of Gold Digger'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 Magnificent Bastard in the present.
 * Preacher
 * The Saint of Killers miniseries, which explained how the titular killer became the Implacable Man 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 Big Bad, has his own issue of this, as well, showing how he rose to the position that readers see him in. He gets a Pet the Dog 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.
 * Fantastic Four, Annual #2, showed the Start of Darkness for Doctor Doom. Reprised in a mini in recent years called "Books of Doom", with added hardcore edge.
 * While the Knights of the Old Republic 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 just about every Sith Lord from the two games at some point.
 * The Judge Dredd 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 Transformers material, Megatron Origin details the origins of... guess who.
 * The gradually unfolding back story of Winnowill and Two-Edge rather took over the second major arc of Elf Quest. We got to see exactly how and why both ended up such raging twisties.
 * 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 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 Nazi Germany, the Holocaust, the Soviet Union, and Red Scare 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 mutant in the Marvel Universe would end up a Well Intentioned Extremist.
 * "Tales of the (X) Corps" strips in Green Lantern and Green Lantern 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.
 * Friday the 13th: Pamela's Tale by Wildstorm.
 * Reverse Flash: Rebirth tells the origin story of Professor Zoom, the Silver Age Evil Counterpart 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 Bad Future where The Earth Is Never Doomed, so he kind of started... acting out.
 * Captain Marvel: Black Adam'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.

Fan Works

 * In the Puella Magi Madoka Magica doujin, "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.
 * We also see this trope in another Madoka fanfic, Stars Above a crossover with Lucky Star.
 * There's a Tumblr roleplay that crosses over X-Men: First Class with the alluded-to-in-canon 1960s era of 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 Anti Villain status.
 * In Through a Diamond Sky, Clu is a Jerkass, but not the dog-kicking Complete Monster of the film. At the end of the story, he's.
 * It's also the fact that he was jealous of his creator when it came to Jordan, saw that the Isos  Having Tron totally blow off his fears and scold him didn't help.
 * The Pony POV Series has the Origins arc, which shows the backstory of Celestia, Luna, and Discord, and therefore serves as the latter's Start of Darkness.  From that point on, he was the Big Bad Complete Monster 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!

Films -- Animation

 * Toy Story 3 gives us a Flash Back of 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."
 * A tie-in storybook based on Disney's The Lion King was actually about Scar's backstory which explains not only how and why he became the series' Big Bad, but also how and why he got his scar in the first place, as well as his real name.
 * According to his backstory, the evil Toad from Flushed Away 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.
 * Megamind narrates his own start of darkness being the villain to Metro Man back when they were school kids.
 * In Kung Fu Panda, 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 help lead to his Face Heel Turn.
 * Beauty and the Beast could be considered this for Gaston, he being the only Disney villain who doesn't start out evil.
 * However, he's already a Jerkass and pretty much an illiterate villianous character from the beginning. It's pretty clear from the beginning that Gaston will take Belle by force if he has to.

Films -- Live-Action

 * The trilogy of Star Wars prequels, showing how the Empire was formed and how Anakin Skywalker became Darth Vader.
 * Freddys Dead the Final Nightmare has shades of this.
 * The Texas Chainsaw Massacre the Beginning.
 * X Men First Class is this for Magneto (and Mystique).
 * Thor has Loki transform from a guy jealous of his older brother to a full-on Woobie Destroyer of Worlds.
 * In fact, especially in light of his appearance in The Avengers, the movie Thor was really mostly a tragedy about Loki falling apart and going insane on Asgard, interspersed with a Fish Out of Water rom-com about Thor meanwhile learning some humility on Earth. If it wasn't called 'Thor' you might be genuinely confused about who was supposed to be the main character, although Loki is clearly the villain. It's not unheard-of for the villain to carry the story.
 * The 1951 Alistair Sim film of A Christmas Carol explores this during the Christmas Past sequence, more so than other adaptations.
 * The flashbacks in The Godfather Part II show how Vito Corleone got to where we saw him in 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 effectively replaces him in the neighborhood. His evolution is complete when we see him travel to Sicily to avenge his family's murder. All of this is a parallel to his son's Protagonist Journey to Villain in the present-day parts of the film.

Literature

 * Hannibal Rising is a poorly-executed Start of darkness for Hannibal Lecter, giving him a Freudian Excuse 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.
 * The Jane Eyre 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 War Craft novel Rise of the Horde, which details the fall from grace of the eredar, along with the beginnings of the evil Horde in the first two games, as you might've guessed by the title, as well as the aptly-named Arthas: Rise of the Lich King.
 * The Star Trek Destiny trilogy reveals the origins of the Borg Collective.
 * A minor example in the Star Trek the Lost Era novel The Art of the Impossible. Corbin Entek, a Cardassian Obsidian Order villain from a highly popular episode of Star Trek Deep Space Nine, 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 Star Wars Expanded Universe has several examples:
 * Outbound Flight serves as a Start of Darkness of sorts for 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 Dark Rendezvous has several flashback scenes that explore Count Dooku's past and gives him a very convincing SOD backstory.
 * The Han Solo Trilogy by A.C. Crispin features a character who appeared first in Dark Empire, 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 the reward. Crispin shows us in her prequels what a good and even heroic guy he used to be, and eventually what happened to change him: he was captured, tortured, and crippled for life.
 * 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 was his Moral Event Horizon.
 * Warhammer 40000 novels:
 * The Blood Angels short story "Blood Debt" serves as one for.
 * Thousand Sons serves as one (a REALLY tragic one) for the Thousand Sons, especially for Maginus the Red. Also confirms that the
 * The entire Horus Heresy is one big Start of Darkness, only made worse by the Foregone Conclusion. Good luck getting attached to people you know are going to die and/or commit a sharp Face Heel Turn.
 * Babylon Five has "Deadly Relations -- Bester Ascendant".
 * Wisdom's Daughter: The Life and Love Story of She-Who-Must-Be-Obeyed by H Rider Haggard details the origins of Ayesha, the Big Bad of She.
 * Fate Zero is mostly a retelling of the Fourth Grail War, making it the prequel of Fate Stay Night. 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.
 * In Dead Souls, Chichikov and Plyushkin started out as decent people, and there's a Cry For The Villain in revealing how both of them descended into what they are now.
 * In Hart's Hope, a chapter is devoted to explaining how eventual Big Bad 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 being raped in public by her father's killer to cement his claim to the throne.
 * Lord Voldemort from Harry Potter. When we meet his child self in Half-Blood Prince, he's already a Damien Thorne-like Creepy Child with signs of a god complex but after being enrolled at Hogwarts School of Witchcraft and Wizardry, he gets to really have some fun. But then as a teenager, who hasn't wanted to unleash their giant snake on the school?
 * Certain moments in his interaction with Dumbledore seem intended to show both how screwed-up he already was and how completely Dumbledore failed to do anything that was likely to help. After all, in 1937 anybody would have considered the best way to convince a kid that stealing is wrong and he shouldn't keep doing it is to show he can't get away with it anymore. Instead what this meant was that Tom understood he was going to have to fight for the power to be safe all over again in the wizarding world, and that magical people weren't going to like or understand him any better than normal people did. Psychopaths are still human, even if their sense of empathy is wrecked.
 * Yes, just think--if Tom had been taught to have more faith in the system, he could have become Minister for Magic legitimately!
 * The Doctor Who Virgin Missing Adventures novel The Dark Path tells how the Second Doctor sees his old friend Koschei become the Master, due to Love Makes You Evil. This may or may not be compatable with the Start of Darkness shown in "The Sound of Drums".

Live-Action TV

 * Barney in the first season episode "Game Night" of How I Met Your Mother. We learn how he evolved from a long-haired whiney guy into the Barnacle.
 * The Master gets a some of this in the Doctor Who 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.
 * 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.
 * The Volume 2 story arcs in feudal Japan show the Start of Darkness for Adam 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 The Company.
 * In season 5 of Buffy the Vampire Slayer, Spike gets a Start of Darkness episode called "Fool for Love".
 * The Cold Case episode "The Woods" explores the background of a Serial Killer who made his debut earlier in the season.
 * In The Sarah Connor Chronicles, the two part episode "Today is the Day" does this for Jesse.
 * The Criminal Minds 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".
 * 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.
 * 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 wife, is ordered to oversee a Nazi death camp and eventually slides into becoming a Complete Monster that only Heinrich Himmler could admire.
 * Several non-consecutive episodes of Xena: Warrior Princess dealt with how Xena became a Warrior Princess.
 * There were also episode detailing Callisto's rise.
 * Each of the Big Bads 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 only the worst in people; when she was de-Bronzed in the present, she saw things had only gotten worse.
 * Walter Sykes was corrupted as a child by an artifact that let him walk; when it was confiscated by Warehouse agents (specifically, ), he became obsessed with getting it back and getting revenge on the Warehouse for taking it away.
 * Rumplestiltskin in Once Upon A Time:
 * "The Stable Boy" does this for Regina.  Well, let's just say someone's True Love ended up dead, and Snow White ended up on the wrong end of a vendetta.
 * Smallville is this for Lex Luthor. By Season 7 he's pretty much become the megalomaniac we all know and love but Your Mileage May Vary as to when exactly he crossed the Moral Event Horizon.
 * Morgana Pendragon gets a similar treatment in Merlin though in terms of personality, she's more Magneto than Lex Luthor. By Season Three, she's nasty, by Season Four, she's evil, though still a Well Intentioned Extremist.
 * Spartacus: Gods of the Arena showed how Batiatus and Lucretia's ambitions led the to compromise their morals and become the utterly corrupt Manipulative Bastard and Bitch they are in Blood and Sand.

Music

 * Doctor Steel's Lament for a Toy Factory.

Multiple Media

 * The Bionicle web-serial Mutran Chronicles and a scene from the book Swamp of Secrets reveal just why the formerly benevolent 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.

Radio

 * Yet another Start of Darkness for the Master in the Big Finish Doctor Who 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.


 * The audio drama series I, Davros shows the early life of everyone's favourite Dalek creating Mad Scientist. Interesting in that he isn't given any Freudian Excuse, and you don't gain any sympathy for him, just understanding.

Video Games

 * Metal Gear Solid 3: Snake Eater 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 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 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.
 * Metal Gear Solid Portable Ops 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 Metal Gear Solid Peace Walker fully sprouts Big Boss' Face Heel Turn.
 * Super Robot Wars Original Generation Gaiden features the Start of Darkness of one of MX's Big Bad 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 Face Heel Turn (since Chars Counterattack is part of Alpha 2) makes even more sense then it's UC Gundam verse reasons. Basically, during the course of the plot, he watches humanity keeping picking the Too Dumb to Live options and the horrifying results, and this disillusions and pisses him off enough to decide a Colony Drop is actually a good idea.
 * Sengoku Basara 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 Matsunaga Hisahide, who proceeds to humiliate the hell outta him, and this causes him to become drunk with power, leaving Keiji and doing a lot of atrocities later on.
 * The Mass Effect novel 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 Knight Templar.
 * The comic Mass Effect: Evolution is one for The Illusive Man and Cerberus.
 * About one third of Crisis Core is spent on telling us how Sephiroth became the Magnificent Bastard and One Winged Angel he is in Final Fantasy VII. 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 note the Epileptic Trees 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 Crisis Core 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 'Break the Cutie'.
 * ''The Legend of Zelda
 * Ocarina of Time is the Start of Darkness for Ganondorf, explaining how he became the King of Evil Ganon.
 * In Wind Waker,, Ganondorf's backstory was expanded by revealing his motives for conquering Hyrule in the previous game.
 * Likewise, The Minish Cap is the Start of Darkness for Vaati, and explains his origins as a Minish sorcerer's apprentice.
 * Kagetsu Tohya fleshes out Roa's start of darkness with the Crimsoon Moon and Drinking, Dreaming Moon scenarios. Roa actually wanted to achieve immortality because he fell in love with Arcuied and wanted to be with her for eternity, but mistook that feeling for hate and thought he wanted to torment her for eternity.
 * 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 Live a Live, the hidden Chapter explains just who and what "Odio" is, and what made him into the demon of hatred influencing the various end bosses.
 * Dragon Fable's Fire War is a Start of Darkness for Drakonnan..
 * In the 1st Degree 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.
 * Nemo's backstory in A Promise Unforgotten would certainly qualify.
 * Baten Kaitos Origins shows how Geldoblame came to be in control of The Empire, and how he went from Verus' prissy Yes Man to a megalomaniacal Evil Overlord.
 * As seen in a flashback, the death of Sophia in Xenogears was the Start of Darkness for Krelian and Grahf.
 * Resident Evil Darkside Chronicles acted as the Start of Darkness for Jack Krauser.

Visual Novels

 * About one-third of Higurashi no Naku Koro Ni Kai is spent giving 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.

Web Comics
"... he's completely and wholly unapologetically evil, but more to the point, he's kind of a dick."
 * The Trope Namer -- admittedly more recent than most of the other examples here, but it's still a pretty cool title -- is Start of Darkness, prequel to Order of the Stick detailing Evil Overlord Xykon and his Dragon Redcloak's past. Of course Xykon, unlike most, is astonishingly evil from the get-go. We get to see him become more evil... and competent. 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 Moral Event Horizon.


 * The very first page of the comic 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, he loses his ability to enjoy simple pleasures such as the taste of coffee.
 * On an even weirder note, Burlew makes a point of not giving away Belkar's backstory in On the Origins of PCs 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... Entirely made up, it turns out, spun in order to gain roleplaying XP.
 * MAGISA -- The villains in this comic pretty much had miserable lives before they became villains.
 * In The Inexplicable Adventures of Bob, Fructose Riboflavin has been the greatest criminal in the Nemesite Empire for the better part of two thousand years. But he Used to Be A Sweet Kid. Then his dad died...

Web Original

 * The Spoony Experiment spoofs this in its April Fools Day review of the original Final Fantasy. 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 Mega 64 reveals how Dr. Poque became the Mad Scientist he is today.
 * Doctor Horribles Sing Along Blog 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 Protagonist Journey to Villain.
 * Super Mario Bros Z 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.

Western Animation

 * The Venture Brothers offers a Start of Darkness for Phantom Limb in "The Invisible Hand of Fate." At one time he was a Mad Scientist 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 Gambit Pileup.
 * Powerpuff Girls: 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.
 * The main purpose of the four-part Gargoyles episode "City of Stone" is to provide a framing story for one of these for Demona and Macbeth.
 * The Batman's episode "Riddler's Revenge", depicting Edward Nygma's gradual transformation from geeky, unappreciated kid to murderous costumed criminal.
 * Batman the Animated Series
 * 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
 * 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 Anti Villain Woobie.
 * Temple Fugate, a Schedule Fanatic, decided to take a break from that schedule at the suggestion of the future Mayor Knox and things went horribly wrong, costing him a court case. Temple snapped and vowed revenge of Knox, becoming the episode's titular villain, the Clock King.
 * In Darkwing Duck, an episode is dedicated to the origin story of Reginald Bushroot, and how he became a villain.
 * In The Fairly Odd Parents episode "The Secret Orgin of Denzel Crocker," it is explained how Crocker became obsessed with fairies and why he's so bitter toward his students and life.
 * Nerissa of WITCH gets one for both her comic and cartoon selves.
 * The Wakfu special episode "Noximilien" shows how Nox, the Big Bad of the main series' first season, became such a Woobie Destroyer of Worlds. Essentially, the discovery of the Eliacube -- an extremely powerful Amplifier Artifact (and, unfortunately, Artifact of Doom) -- and Noximilien's subsequent obsession over it led him to neglect his family, which resulted in their loss. He did not take this well. At all.
 * The Boondocks episode "The Color Ruckus" shows the events in the life of Uncle Ruckus (no relation) that lead him to becoming a Boomerang Bigot.
 * While Samurai Jack'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 ultimate evil which the Gods fought among the stars.
 * The Transformers Animated episode "Along Came A Spider", where we find that Blackarachnia's hatred against Autobots began when Optimus Prime and his friend 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.
 * The Dr. Robotnik of Adventures of Sonic the Hedgehog 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.
 * Avatar: The Last Airbender 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;
 * Skeletor got one in the 2002 Masters of the Universe reboot. Turns out he was a powerful wizard trained by Hordak who wasen't completely bad (or at least not totally 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.