Ron the Death Eater/Video Games

Examples of in  fan works include:

Fire Emblem: Three Houses
Thanks to Edelgard being one of gaming's biggest examples of Draco in Leather Pants, it's only natural that the main three faction leaders opposing her are all given this treatment to some extent.
 * Poor Rhea is easily the biggest victim of this trope. Being the shady archbishop of a similarly dubious-looking church in a genre where evil churches are the norm means that she was playing with a stacked deck from the onset, but even when her many good traits become apparent, many fans choose to ignore them and make her out to be as bad, if not worse than Those Who Slither in the Dark.
 * A recurring problem in the game is that many characters' lives are ruined, or at the very least, plagued by issues regarding their Crests, special powers carried down through their bloodline. Blame is often laid at Rhea's feet for "perpetuating the Crest System" despite the Church's doctrine disavowing Crest-based elitism, and the people actually responsible for antagonizing victims of "the Crest System" are quietly ignored when Rhea isn't being blamed alongside them.
 * Others claim that Rhea is bigoted and intolerant towards foreigners and non-believers, and in turn blatantly ignore the foreigners and non-believers Rhea has employed at the church (such as Shamir and Cyril) and allows to attend Garreg Mach Monastery's Officers Academy (such as Petra and Dedue). In fact, the Church of Seiros stands against intolerance, and one of the reasons why the radical Western Church hates them is because they aren't xenophobic bigots. Some of this stems from Claude's misconception that the Church of Seiros preaches xenophobic doctrine, but even that ignores the fact that it's a misconception and that Claude realizes that he's wrong about the church and Rhea over the course of the Golden Deer/Verdant Wind route.
 * Speaking of the Western Church, Rhea catches flack for being "unreasonable and tyrannical" when she orders the execution of multiple Western Church members at the end of Chapter 4, as well as sending the Knights of Seiros to kill Lord Lonato when he's rebelling in Chapter 2. While she does act creepy and fanatical, neither Lonato nor the Western Church are blameless victims. Both lead armed insurrections that would get plenty of innocent people caught in the crossfire, with said insurrections being attempts on Rhea's life. Rhea was content to live and let live before they tried to murder her and anyone else that got in their way.
 * While Rhea does in the Crimson Flower route, she's still a far more heroic character in 3/4 routes, and even here only crosses the line as a result of having every single Trauma Button pressed simultaneously by Edelgard and Byleth, forcing her to relive the  and turning her nearly insane as a result. This doesn't stop fans from declaring that her Crimson Flower-exclusive homicidal insanity is her true self no matter the route.
 * Rhea's motivations are often boiled down to being a selfish and childish desire to . And while a desire to is partially the truth, the other part conveniently left out is that.
 * Dimitri is an earnest, humble, and kind-hearted man with a dark side, but Edelgard fans often treat his as the mask slipping off and showing Dimitri at his basest, true self. Never mind that it stems from the trauma of witnessing his father's violent murder and the near-genocide of the people of Duscur, never mind that, never mind that , it's far easier to label him a  and call it a day.
 * Crimson Flower is the route where he's hit the hardest with this, despite the fact that he's perfectly sane and a clear-cut Hero Antagonist defending his homeland from Edelgard's invasion there. When he rightfully calls out Edelgard's bullheaded commitment to murder and violent conquest, she essentially pulls an anemic "No U!" on him by condemning him for "reconquering and killing in retalation", a sentiment her fans tend to agree with wholeheartedly.
 * While he avoided this treatment at first, even Claude would fall victim to demonization at the hands of hardcore Edelgard fans., but his detractors claim that he's exactly as untrustworthy as his façade would indicate and claim that despite her methods being the antithesis of his own. Some of it stems from , but it ignores the fact that he's clearly shooting the bull and willingly pandering to Edelgard's perception of him given how his portrayal in other routes don't even hint at a genuine desire to.
 * While he avoided this treatment at first, even Claude would fall victim to demonization at the hands of hardcore Edelgard fans., but his detractors claim that he's exactly as untrustworthy as his façade would indicate and claim that despite her methods being the antithesis of his own. Some of it stems from , but it ignores the fact that he's clearly shooting the bull and willingly pandering to Edelgard's perception of him given how his portrayal in other routes don't even hint at a genuine desire to.

Touhou

 * The Chinese Touhou doujin Yuyuko's Yukkuri Farm goes to the extreme and has Yuyuko as a literal baby eater (warning: link is to Danbooru and has NSFW ads).
 * A dark fic author by the name of Stripe Pattern believes Byakuren, one of the unambiguously good characters in Touhou, is a psychotic monster in the doujin Love and Peace.
 * Portraying Sanae as a sadistic youkai tormentor/killer is a big enough trend among doujin artists and in fanarts to have its dedicated pool on Danbooru. To no one's surprise, Kogasa is her main victim, and Sanae's awful treatment of her in Undefined Fantastic Object is probably what started the trend.
 * Mei Miya's murder mysteries inevitably turn some neutral or nice characters into villains (spoilers marked if anyone wants to read them):
 * Murder of the Shining Sun
 * In Seasons Lit with Gold,

Other works

 * Nerf Now did this to The Legend of Zelda series star Link, and made it look easy. In the comments, readers are seen not only developing the theme, but approving "Hey! Listen!" in more than one way.
 * A later comic did the same thing to Megaman and Dr. Light.
 * Spyro the Dragon: Ember was included in The Legend of Spyro: A New Dawn mainly to defy this trope because the author was sick and tired of her getting this treatment by the fandom. Quite a few readers agreed and she ended up being the Ensemble Darkhorse.
 * This artist from Deviant ART writes the eponymous protagonist of Mega Man this way simply because he destroys their favorite robot master(s).
 * Endlessly done to Luigi in Super Mario World ROM hacks. Some examples:
 * SMW YEAHHH has him as the true villain and final boss
 * Brutal Mario looks to be the same, as implied by this early final overworld map. Note him riding in the clown car and the giant neon letters on the castle. Also, it does the same to Peach (who's shown to be working with Luigi, and can be seen as an unfinished boss in game) and Mario (who's apparently trying to take back the kingdom he ran as a dictatorship beforehand).
 * S Mario has this, according to the translation raocow is working with. -->Luigi: "Brother, I've become a wielder of Black Magic."