"No." he said meanly. "I don’t give a darn what Voldemort does to Draco. not after how much he misbehaved in school especially with YOU Enoby." he said while he frowned looking at me. "Besides I never liked him that much anyway."
—Albus Dumbledore Albert Dumblydore (in one of the more insane examples of this trope), My Immortal
Harry, in Slytherin. Ron severs ties with Harry the second he's sorted into Slytherin, giving him "a look of deep hate". He assaults Hermione in their first flying lesson, and in his second year nearly kills her with a spell; expelled, he ends up attending Durmstrang (often referred to as the "evil" school, despite Viktor Krum being a student there).
Harry and Hermione's secret: "Did you know [Ron] tried to rape last year?" Presented entirely matter of fact and never referenced again.
Harry: (to Ron) I mean, most of the time, it's one of the things I like best about you, that things are so... simple for you. But Malfoy's been raised for this, trained for it. He told me once that a murder is just taking control of someone in a final sort of way, like it was nothing. I knew he'd be a Death Eater then, a murderer. I should've listened to my instincts.
Hermione: Oh, Harry. We all could have guessed it, but we didn't want to believe it of him...
Ron: You two sure do turn on a knut, don't you?
Also subverted in the first chapter of What Would Slytherin Harry Do?, where it looks like Ron has joined Umbridge's inquisition until Harry reveals near the end of the chapter that he was actually a Double Agent.
Molly: Ginny, you've got to calm down. Minerva has caught you four times with different boys.
Ginny: That just goes to show that she's not as informed as she thinks. She missed five others, Mum. Look, with everything I'm doing for you, you can cut me some slack. That pathetic half blood upstairs must be a eunuch. I haven't managed to get a bit of action out of him.
This is toned down in the revised version, in which Ginny genuinely likes Harry, but the reason why she is with Harry is because she thinks he is going to die fighting Voldemort and wants to give him something to be happy for before he marches to his death.
In The Seekers, the remains of Tom Riddle's personality resurface in Ginny after Harry and Cho hook up.
The Girl Who Lived does this in a truly bizarre fashion. At first, Ron is more or less his canon self, but as time went on most of his good moments were handed off to Hermione or Neville or Rose. This left Ron as a lazy idiot who begged Rose to let him copy her homework, only for her to roll her eyes and condescendingly tell him to do it himself. The author also makes his bad moments (like the fight in The Goblet of Fire appear far worse then they are, giving Rose the chance to fight back. Ginny, meanwhile, is initially presented as Rose's best friend and fellow Druidess (along with a heavy amount of Les Yay), but after rewriting Order of the Phoenix she appears to lose with favour the author and by extension Rose, and is more or less replaced by Luna. In the brief amount of time she's shown in Half Blood Prince she's a jealous shrew who wrongly picks on Fleur and yelled at by Rose. Helps that the author is a committed Harmonian, explaining the Ron and Ginny bashing.
Partially Kissed Hero would be a standout example of Evil!Dumbledore, had the fic not later on gone entirely off the rails. (Not that Dumbledore's gotten any better; he's just gotten less and less rational, to the point where the plot seems to be random'ing all over the map...) Dumbledore is presented as a Complete Monster who secretly controls all of Wizarding Britain, to the point where Voldemort is an almost entirely irrelevant sideshow. Snape is also Flanderized into Dumbledore's equally evil sidekick.
Harry: Think, Hermione! If you wanted to rule the Wizarding World, what would you want that Dumbledore doesn't already have?!?
The very first Harry Potter fanfic, Harry Potter and the Man of Unknown, did this to an extent. While not Obviously Evil and maintaining the pretense of his canon personality, Dumbledore was nonetheless revealed to have given Harry to the Dursleys over his mysterious uncle (the Anti-Hero protagonist) and his reason for doing so was fairly dumb.
In Harry Potter: The Dark Wraith, Dumbledore is a horrendously evil man who steals souls to get stronger to become immortal. Psychopath Ron also quickly emerges after being rejected by Hermione, who then immediately blames Harry for it and wants to kill him. The story wastes no time in derailing both of these characters as Complete Monsters; it does so in the first chapter.
A notable inversion appears in the fanfic, The Lie I've Lived, where Harry actually expected Dumbledore to turn out like this, but was downright surprised to find Dumbledore avert it by stopping himself after realising the extent of his actions thus far. Then he apologised.
For possibly the most extreme and idiotic example of the Dursleys getting this, look no further than a sad story:
"The family is going out to dinner" he began "You will stay here, but you will be somewhere where you can't make any trouble" He said as he grabbed Harry by the neck and dragged him to the garden Shed. He padlocked the door with at least 20 locks.
Child of Grace uses this, along with "alternate universe female Harry" and "Ron hates Harry for not being in Gryffindor", bringing us Holly Potter, a girl who swings between being a Purity Sue and a Jerk Sue and who begins the tale sitting out in the snow while the Dursleys are inside eating dinner. She is quickly established to be skinny, frightened by anyone touching her, heavily black and blue under her clothes from the beatings, and will curtsy to all strangers because the Dursleys had had such manners "all but beaten into her".
Oedipus Flower asks what Harry would be like without a fragment of Voldemort's soul inside of him. It Gets Worse. He ends up having sex with his sister and his mother (both willingly and at the same time), then murders his brother and father. At least he gets arrested at the end.
"Who would've thought that we'd be hoping for Voldemort to save us?" I said. "I guess it goes to show how evil Ron is that Voldie doesn't seem so bad anymore."
Aspirations inverts the Evil Ginny scenario by having Hermione first turning away from Harry when his name comes out of the Goblet, and then, when he gets together with Ginny, first tries to use a love potion (doesn't work due to the power of love), and then starts learning dark magic. Naturally, she goes rather mad from that. After an attempt to kill Ginny (which backfired - literally), she has a What Have I Become? moment. Put on a Bus later. Ron, however, is just a somewhat bigger jerk than in the books (and is actually trying to help Hermione despite her constant abuse of him).
Hermione's behaviour is retconned in a very weird way. The first chapter has Hermione turning on Harry just after his name came out of the Goblet of Fire, but maaaaany chapters later is revealed that Hermione went to talk with Dumbledore to find a way to get Harry out of the Triwizard Championship (implying that she knew Harry was innocent) only to find herself under some kind of charm that apparently blocks her from acting normally.
Fanfics which indulge in Ron bashing also tend to portray the wizarding world as ridiculously archaic and obsessed with blood purity.There are a number of fics where Ron wants to teach Hermione her place in the wizarding world since she's just a mudblood and begrudges Harry his wealth because he is a "half-blood"..and you wonder why the war was fought at all..sample this piece of gem from the fanfic In this World and the Next where Umbridge becomes minister instead of Kingsley Shacklebolt (since the minister has to be British and a pureblood).Umbridge has this to say after Ron rapes Hermione "The law states that it is impossible for a pureblood to rape a muggle born or half blood, the girls should be delighted to receive the attention of such noble wizards"....Voldemort looks like a seriously misunderstood dude in comparison..
Well, you actually can imagine canon Umbridge saying that; the part that qualifies for this trope is where the Weasleys joined the parade. But if you thought that was over the top, wait until the later chapters where Harry and Hermione cold-bloodedly murder and torture several Weasleys in the past, before they've committed any of their chapter 1 crimes, and are presented as perfectly justified in doing so! (Granted that Percy was plotting to murder or at least assault someone due to insane jealous fixation, there's still ways to handle that short of feeding him to a Cerberus. And 'being an ill-mannered jerk' is not remotely enough justification for literally castrating Ron...) Well, Hermione has some angst, and actually convinces Harry to merely leave Ron as a beaten, traumatized shell of his former self and also turned into a girl. That's all right then.
Another example from this author is More Important Things, where the diary Horcrux succeeds in killing Ginny and Voldemort subsequently takes over several years early. Ron happily jumps on the bandwagon of this pureblood-favouring society, to the point where he goes out in public with a couple of partially clothed girls on leads, and orders Hermione to "get down on (her) knees and attend to (his) needs now" in the middle of the street because she's a lowly Muggleborn.
All over the place in My Immortal. The Trope Namer himself is merely turned into a "goff" friend of Ebony's (and changes his name to Diabolo), and despite Harry/Draco being a couple in the fic, Ginny is only mentioned briefly as one of Ebony's clones. At the same time, however, Dumbledore, Snape, and Lupin all get Death Eater'd. While he's certainly out of character, exactly what Dumbledore does that's so evil is a bit of a mystery. The quote at the top of this page is practically the only exception to his portrayal as a good-hearted, senile moron, but the only thing Ebony and friends care about is that he's a "poser". It's also weird that Snape is considered a "prep" when the canon Snape is arguably the most gothic character in the whole series. Furthermore, the portrayal of Snape and Lupin as "pedos" seems to come completely out of left field.
McGonagall gets a dash of this too, the most glaring example being when she magics chains onto Ebony, Draco, and Vampire, and then leaves them to be tortured by Snape.
Played half straight in the very, very NSFW fic Not Go Gentle- while Ron does rape Hermione, he was being manipulated by Ginny, who is a straight example, being in love with Voldemort, though he at least is only using it as a source of loyalty.
The author LOVES this trope. Most of his stories contain large amounts of Weasley-bashing, followed by incrediblyinventivepunishments. His fanfics have Ginny turned into a shrieking harpy who attempts to rape Harry, Ron's Book Dumbflanderized into such stupidity that he can't tell the difference between one hole and another (better than his treatment in subsequent fanfics, where he's raped repeatedly by the ghoul in his house and a harem of watersports-loving Slytherins), and Mrs. Weasley in a lesbian relationship with Dolores Umbridge.Let that sink in a bit.
The above mentioned story also features Dominatrix Hermione, Cowboy Voldemort, Wrestler Voldemort, Evil!Alternative Universe!Harry, Super Masochist!Ginny, and more gratiutious sex than a shelf full of porn. One wonders what exactly readers were expecting.
Lovely Sympathy is a story taking place post-Deathly Hallows but with one big difference: Snape lives. Of course, this has the effect of turning Ron into a maniac who regularly abuses Hermione, including using two of the unforgivable curses on her, to get him out of the way so Hermione can end up with Snape.
Minerva
Mr Weasley kidnapped Miss Granger from behind my back, used crutiatus and then fled. She is fine, but refusing to let me leave, cover needed for my lesson. Will explain more later but it looks like Harry is in big trouble.
Severus Snape
Bonded. Starts off when the Dursleys try to kill a six year old Harry (Dudley participating). Dumbledore believes himself to be good... but his idea of ensuring the survival of good is "Get Ginny to have a child with Harry, get Harry killed, let the weeping widow raise a heroic child who'll be too disgusted at dark magic".
The 'Abusive Dursleys' plot is in full-force within the first two paragraphs alone:
Less than half an hour later his uncle who burnt his tongue on a gulp of hot coffee then proceeded to pound the child repeatedly for half an hour leaving him unconscious with a broken left arm and bruises to 80% of his body. He left the right arm unbroken so the boy could do his chores.
The Last War. Infamous "Harmonian" screed that satanizes Ron and Ginny, chickifies Hermione and makes Harry a Jerkass. To the point that, when Hermione kills Ron remorselessly after spending several years whining endlessly about how abusive he is to her and Harry beats up Ginny for being soooo evil, these actions are seen as good things.
The Unfortunate Implications are turned Up to Eleven with many, MANY refernces to Hermione being really beautiful as contrast to Ginny being an ugly fat bitch who lost her good looks right after marrying Harry. So of course it's okay for Harry to cheat on the fat slut Ginny with pretty pretty Hermione!
Proof that not all fics that do this are bad: Harry Potter And The Nightmares Of Futures Past does this to both the Dursleys and Snape, justified by the author as taking the abuse seriously (the frying pan being swung at Harry's head being classed as assault), and the last book not being released when the fic was started (the writer therefore did not know whether Snape would be redeemed or not). Dumbledore gets this slightly as a Well-Intentioned Extremist who believes in the ends justifying the means.
Most of the entire British Wizarding World is given a full dose of this in Harem War, (M), a fic which pretty much tropes the entire wizarding society, mocking virtually all the pureblood culture and presenting many of the men most people dislike (Death Eaters, Fudge, the works), as perverts who possess concubine slaves and various other parts I don't plan on spoiling. To tropes Molly standard, Draco standard, Dumbeldore standard Harry hater and the main seller of concubines (AKA, any girl without a father or other designated magical guardian, a list that would at various times feature Hermione, Luna, The Patil's, Lavender, Cho and many OC's, Snape standard Lucius standard and Ron standard taking on full Trope form. However, it also shows off several troped characters pleasantly. Ginny originally believed to be in her troped form but was proven to be innocent, the Dursley's were shown to be under personality altering potions, Remus seemed slightly of the trope variety but was shown to be merely misinformed and thought he was doing the right thing, and Pansy was shown to be sort of half half....
Thankfully averted in the Rise of an Alpha series (Becoming Alpha and Return of an Alpha. While, at the start, Ron dislikes Harry for being a Slytherin, Harry's kindness and efforts to have the whole of Hogwarts working together, as well as saving Ginny from the Tom Riddle's Diary, have him slowly mellow out and, while he doesn't become as close to Harry as the canon Ron, he eventually becomes a friend and partner in what Harry is doing.
Lily's Defender does this to James Potter and Sirius Black. After getting off on the wrong foot with Lily on the Hogwarts Express, they immediately turn racist and prejudiced against Muggle-borns, believing they are too "stupid" to attend Hogwarts, despite the fact that there is no evidence James and Sirius held those beliefs at any point in their life in the actual canon and openly rejected them at several points, Sirius hating his family for being pureblood fanatics and James repeatedly asking Lily out despite her constant rebukes.
In Nothing in Return, it is revealed around chapter 30 that not only is Ron evil, the real Ron been dead ever since the contact with one of the brains inside the Ministry, which used to belong to a Death Eater's relative. Dumbledore seems to be rather manipulative, but as of chapter 32, the extent is unclear.
In The Phoenix Syndrome by apAidan, which is one of the very few epilogue-complaint bashfics, Ron is a lazy jealous git who never loved Hermione and only married her so that Harry would never be happy. He also gladly cheats on her with every woman in sight, including Pansy Parkinson, and is so stupid that he never notices Pansy using their trysts as opportunities to steal and photocopy classified Ministry documents from Ron's belongings. But that's still nothing compared to the delusionally insane sex-addicted sadistic psychopath that Ginny's turned into, and that's before you factor in Ginny's having been possessed by the horcrux of Bellatrix Lestrange.