Flanderization

Flanderization is a trope that refers to the act of taking a single trait from a character and exaggerating and amplifying it more and more over time until it completely consumes the character. Most always, the trait/action becomes completely outlandish and it becomes their defining characteristic. Sitcoms and other comedy shows are usually the ones to suffer this, due to the writers doing anything they can to get a cheap laugh from the audience, even if it means sacrificing a character's personality. Either there are out of character personalities that are counted as against the characters we known in love, or there are personalities that will make you have no choice but to lose all of your respect you would have had for all the characters.

Although, flanderization doesn't always make the characters turn out awful. Some flanderization can make them more funnier and likable. It depends on how the character is flanderized. This good side of flanderization is most noticeable in Thor from the MCU, who became a less serious and more badass hero.

The Simpsons, being the series which spawned this trope's very name, has this almost across the board. Over time, the series has, in many ways, become a symbol of this trope in its purest form.

In the topic of Flanderization, the American animated sitcom King of the Hill is a notable example of a series that used Flanderization. This series is known for giving flatter characters new aspects, then focusing on them, thus creating the sense of Flanderization at the same time as they get Character Development.

Notable victims of flanderization

 * Ned Flanders (The Simpsons; the trope namer, went from merely enjoying going to church to being obsessively religious and overly nice, and then later an obnoxiously intolerant bigot who will lash out at anyone that doesn't support Christianity)
 * Moe Szyslak (The Simpsons; became the show's punching bag, even before he was the show's punching bag, he was the main punching bag whenever he gets prank called by Bart, other things else, either done in a funny way or not so funny way)
 * Homer Simpson (The Simpsons; became a selfish and sometimes crazy moron.)
 * Marge Simpson (The Simpsons; turned into an overprotective mother who's no fun at all, what is completely against her character. This happens in the episodes where the episode is disliked by fans, considered boring, or is just plain bad)
 * Bart Simpson (The Simpsons; turned into a borderline sociopath, though not as bad as Peter Griffin)
 * Lisa Simpson (The Simpsons; became a know-it-all Social Justice Warrior, which is far too against her character)
 * Maggie Simpson (The Simpsons; became a flawless Mary Sue, despite the fact that she is likable and cute)
 * Donald Duck (Disney Cartoons; the trope codifier; became a meanie, except in the educational shows)
 * Garfield (The Garfield Show; became an unlikable slob)
 * Jon Arbuckle (The Garfield Show; became an idiot)
 * Nermal (The Garfield Show; became a jerk)
 * Harry Potter (Harry Potter novels 5-7; became an unlikable jerk)
 * Peter Griffin (Family Guy; Season 7-present; became an insane, rude, hypocritical, selfish, psychopathic, and an egotistical person)
 * Lois Griffin (Family Guy; Season 7-present; became a sex-crazed, abusive short-tempered wife)
 * Meg Griffin (Family Guy; Seasons 6-14; became a punching bag up until Season 14)
 * Chris Griffin (Family Guy; Season 7-present; became a character going in full idiot mode in the worst way possible)
 * Brian Griffin (Family Guy; Season 7-present; his entire personality now amounts to being a "liberal", and became a complete jerk and got even worse when he came back)
 * Glenn Quagmire (Family Guy; Season 7-present; became not just a pervert, but an implied child molester)
 * Stewie Griffin (Family Guy; went from a toddler with the mind of an evil genius to a toddler with the mind of a stereotypical gay guy)
 * In the later seasons of Arthur, Arthur went from being an average kid with an active imagination, to becoming a super serious character with almost no personality. Barely any episodes of his own show focus on him now because of this, and when they do, he often acts even more out of character. He is now often used as a voice of reason for his friends. D.W. has gotten a similar treatment, with many of her personality traits being downplayed in later episodes. The Brain went from being an incredibly smart kid who still liked things other kids did, to being someone who can't accept almost anything unrealistic. Sue Ellen went from being a tough, but friendly, kid, and the only student capable of intimidating Binky, to being someone unable to stand up for herself when bullied.
 * Ed (Ed, Edd n Eddy; Seasons 5-6; became a to dumb to live idiot, although he is still likable)
 * Edd (Ed, Edd n Eddy; Seasons 5-6; became a constantly complaining goody two-shoes)
 * Eddy (Ed, Edd n Eddy; Seasons 5-6; became an unlikable and violent loudmouth)
 * Jimmy (Ed, Edd n Eddy; Seasons 2-6; became a vengeful crybaby)
 * Spongebob Squarepants (Spongebob Squarepants; Seasons 6-8; became an obnoxiously happy moronic idiot and a crybaby in some episodes)
 * Patrick Star (Spongebob Squarepants; Seasons 1b-5; 6-8; he suffered two flanderizations; he started out as kind of dumb but fairly intelligent, but as Season 1 progressed, he became more stupid and immature and eventually his stupidity became his main, defining trait (This was a good flanderization that made him funnier and more memorable); then, in Seasons 6-8, he had second flanderization (which wasn't a good one). He essentially became brain dead, with his actions becoming dangerous at times. He also became a selfish jerk. True, Patrick had his jerky and antagonistic moments in earlier seasons, but these moments pretty much became a major part of him in these seasons. Then, in Season 9 onwards, he finally got better after years of complaints from fans and critics)
 * Squidward Tentacles (Spongebob Squarepants; Seasons 6-8; became more of a butt-monkey/punching bag than he already was, with his hatred of SpongeBob and Patrick increasing to the point where it's shown a few times that he even wants him/them DEAD; his temper also shortened considerably)
 * Mr. Krabs (Spongebob Squarepants; Seasons 6-8; turned into an even bigger black-hearted and self-serving greedy monster who, in one episode, terrorized Plankton to the point where he attempted suicide (yes, seriously) and Mr. Krabs just brushed it off like it was nothing; his love for money also became over-exaggerated)
 * Phineas Flynn (Phineas and Ferb; went from being an occasionally snarky genius Everykid trying to have some fun during summer vacation to being optimism and enthusiasm personified . It's gotten to the point that if the writers want to pull some O.O.C. Is Serious Business, all they have to do is have him act mildly irritated)
 * Dr. Doofenshmirtz (Phineas and Ferb; once able to take Perry in a fight or actually pose a credible threat, gets progressively more inept and silly, barely posing any sort of challenge whatsoever. His attachment and obsession with Perry is exaggerated to the point he cannot survive a single second without him)
 * Timmy Turner (The Fairly OddParents; was portrayed as essentially a good kid in the first few seasons, who occasionally gave into his selfishness. However, he was still very likeable. However, by about the fourth or fifth season, he became a jerk along with all the other denizens of this hellish parody of sitcom America, including his Fairy Godparents who were summoned to help him the first place. Timmy has returned to most of his original affable characterization by the sixth season onward but it still shows up every now and again, before relapsing back into it in the tenth season upon the introduction of Chloe Carmichael)
 * Cosmo (The Fairly OddParents; was originally simply The Ditz and a bit of a Cloudcuckoolander, sometimes dim but still relatively normal, and perhaps strangest of all, he and Wanda seemed to be on an equal level of airheaded and careless intelligence ("We're two halves of a whole idiot!") Starting around Season 2, he started to become increasingly dumber with each season. Now he's just The Ditz. Just look back at his character in the original Oh Yeah! Cartoons pilot — he was actually a suave and sophisticated guy, barely resembling the character he became. Also, his relationship with Wanda in Seasons 4 and 5 was the foil for a lot of marriage jokes; in a couple of episodes, he claimed to be trapped in the marriage to Wanda and that she had tricked him into it. This characteristic was toned down in Season 6, when the birth of Poof turned them into loving parents)
 * Wanda (The Fairly OddParents; was originally portrayed as being dimmer than Cosmo, believe it or not, then at around Season 1 they shared an equal amount of intelligence. From Season 2 onwards, Wanda became simply the wiser one who chastised Timmy and Cosmo whenever they did something wrong. Then, all her jokes tend to be that she's a total nag, to the point where the Barbarian Hero episode had her become the whip cracking Nagules. Her marriage to Cosmo also became one of the biggest sources of humor on the show, to the point where Cosmo made it appear that he was trapped in the marriage to Wanda; however, this was toned down in Season 6, when the birth of Poof brought them closer together and they are currently revamped as loving parents)
 * Mr. Turner and Mrs. Turner (The Fairly OddParents; they go from busy and clueless to extremely negligent parents who have hinted at times that they don't truly love Timmy, and see him as a burden. This was actually the plot catalyst in an episode guest starring the late Steve Irwin as 'The Bad Parent Hunter')
 * Sheen (Jimmy Neutron/Planet Sheen; became an immature idiot)
 * Hank Hill (King of the Hill; is known for preferring traditional things over trendy new ones. This starts to get overdone in the later seasons; case in point, "Get Your Freak Off". In this episode, Hank is more Amish than the Amish; he's almost medieval)
 * Bobby Hill (King of the Hill; in the beginning, Bobby was a late bloomer, but an otherwise ordinary kid: he was immature and impressionable, but in some ways wiser than his straitlaced family. Bobby's immaturity and impressionability eventually became the entirety of his character, to the point it's difficult to believe he was ever showing any sort of character development at all. Bobby also went from a kid who regularly watched and played sports (football, baseball, soccer and wrestling) to being so bad at, and ignorant of sports that Hank has to explain what a first down is while watching football)
 * Luanne Platter (King of the Hill; started out naive but had her moments of intelligence like being able to fix cars and know when she was being used or taken advantage of, she became increasingly ditzy in later seasons and eventually married an ugly idiotic middle aged hillbilly even though she previously stated she didn't want to marry a much older man, and after she married him she became an idiotic womanchild who acts like a five year old most of the time)
 * Many of the characters in The Amazing World of Gumball began taking rather large levels of jerkiness in season 2, with Darwin being the most notable offender. On the flip side, Darwin also showed an increase in intelligence, as he was sometimes the first one to call out Gumball whenever they were doing something they weren't supposed to. He isn't as bad as he was in season 3, but he still has he moments.
 * The Annoying Orange (The High Fructose Adventures of Annoying Orange; became more annoying than he was in the web series to the point he is not funny)
 * Mayor Shelbourne (Cloudy with a Chance of Meatballs; he began taking rather large levels of jerkass in the TV show adaptation of the film)
 * Scoop (Bob the Builder; became careless and annoying in the Bob the Builder reboot)
 * Muck (Bob the Builder; also became idiotic in the Bob the Builder reboot)
 * Eric Cartman (South Park; became an absolute villain rather than just a jerk; not to mention, his bigotry used to be only targeted toward Kyle)
 * Stan Marsh (South Park; his maturity and intelligence over most of the adult cast has been exaggerated more in the show's run. Initially he was far more child-like and mean spirited. Compare the gang's treatment of Butters in earlier and later seasons, for example. His cynicism and aggravation at others around him was also ramped up to the point where the episodes "You're Getting Old" and "Ass Burgers" created a sharp divide with fans)
 * Kyle Broflovski (South Park; went from being the voice of reason and Cartman's contrast to a stuck-up genius prude and flak magnet, sometimes being almost as much of a Butt-Monkey as Butters. His rivalry with Cartman also increased to the point where it took up B-plots (if not the whole plot) of episodes)
 * Butters Stotch (South Park; started out as one of the "weird" kids but otherwise normal. Now he's an Unpopular Popular Character with occasional moments of brilliance. This Flanderization seems to have been slightly better received. However there are concerns that he risks becoming a Dumb Is Good character if his naïvete increases)
 * Randy Marsh (South Park; became a paranoid coward and a manchild)
 * Twilight Sparkle (My Little Pony: Friendship Is Magic; was initially a fairly lucid if prudish student who simply had poor social skills. As episodes pass, her geeky, finicky qualities are exaggerated more and more, giving her Super OCD qualities and a tendency for neurotic snit fits. Her acerbic qualities also faded, making her more naive and hammy)
 * Fluttershy (My Little Pony: Friendship Is Magic; as originally quiet and timid, but was capable of showing moments of bravery and assertiveness when the situation called for it, like when she made a dragon break down crying in "Dragonshy". Later on, she became increasingly blunt and even outright Cruel to Be Kind when it came to helping her friends or standing up for herself, like when her Brutal Honesty made Rainbow Dash's depression over Tank's hibernation worse in "Tanks for the Memories")
 * Big Macintosh (My Little Pony: Friendship Is Magic; in his first few appearances, spoke normally but also said "eeyup" a couple times, sort of as a Catch-Phrase. As time went on, Big Mac morphed into The Quiet One, only saying "eeyup" and "nope," and virtually nothing else. The few times he does articulately talk past the third season or so are treated as a big deal)
 * Yakko, Wakko, and Dot Warner ( Animaniacs ; started out as Karmic Tricksters who only torment and harm those who have been rude or cruel to them, but several of the later episodes have them bother and harm people unprovoked and be pests just for the sake of doing so. One example that stands out is in "Back in Style", where they are loaned out to guest star in parodies of other cartoons and are complete jerks to the cartoons' main characters when their only conceivable crime is being made by studios other than Warner Bros)
 * Bloo (Foster's Home for Imaginary Friends; started out as being protective over and caring of Mac in the pilot whilst being only slightly mischievous and then became a "jerk with a heart of gold" type of character in the first season, but then eventually he lost the "heart of gold" part and just became a full-blown, straight-up, outright meanie whose jerkiness kept getting worse and worse as the show went on until he finally started leveling off around the end of the series)
 * Brent McHale (Cloudy with a Chance of Meatballs; has the catchphrase of "Uh-oh" from his time as the mascot of the Baby Brent Sardine company. In the first film, he says it pretty often. The sequel, on the other hand, he says it so much it's reached Verbal Tic levels)
 * Earl Devereaux (Cloudy with a Chance of Meatballs; became a rude and manipulative jerk in the TV show adaption)
 * Mater (Cars; became an idiot jerk in the second film)
 * Dib Membrane (Invader Zim; was always something of the Straight Man (at least compared to Zim) but who still seemed a bit manic and gullible in early episodes. By the end he seemed far saner (though still a bit naive), as well as far less optimistic that anyone will ever believe him about Zim. Arguably counts as Character Development, however, since a lot of this would fit with his experiences fighting Zim throughout the series. As well as Dib's (an everyone else's) awareness/obsession/neurosis about the size of his head)
 * Gaz Membrane (Invader Zim; went from being a Creepy Child who would occasionally act overly-dramatically over minor inconveniences to a borderline psychopath who beats Dib up numerous times for perceived slights)
 * Optimus Prime (Became a psychotic killing machine in Transformers 2: Revenge of the Fallen)
 * Thomas the Tank Engine (Thomas and Friends; Seasons 8-16; Same as Spongebob Squarepants)
 * Percy The Small Engine (Thomas and Friends; Seasons 8-16; same as Thomas and SpongeBob)
 * Edward The Blue Engine (Thomas and Friends; Seasons 8-16; became an old paranoid wimp who worries about everything way too much and is no fun at all, unless he is in character depending on what episode it is)
 * Henry the Green Engine (Thomas and Friends; Seasons 8-16; became a paranoid coward, wimp, and a moron)
 * Gordon The Big Engine (Thomas and Friends; Seasons 8-16; became a punching bag and also a pompous killjoy, but in a bad way, even when it comes to him tempting fate or getting his comeuppance, "Bust My Buffers!" is one of the episodes where Gordon just gets tortured and Diesel, 'Arry and Bert don't get punished or scolded for their actions)
 * James The Red Engine (Thomas and Friends; Seasons 8-16; became a pretentious and a complete jerk about his red paintwork without even thinking of others in the slightest, but in "James Gets a New Coat", he gets his comeuppance for boasting about his red paint so much)
 * Toby The Tram Engine (Thomas and Friends; Seasons 8-16; same with Edward and Henry, though, one of the few episodes he did man up was in the episode "You Can Do It, Toby!”.)
 * Emily The Stirling Engine (Thomas and Friends; Seasons 8-16; became a bossy, naggy, short-tempered jerk, and later turned to a really idiotic and dim-witted Mary Sue in the CGI series.)
 * Skarloey The Little Old Engine (Thomas and Friends; Seasons 9-12; became a cowardly engine over almost everything, but got better in Season 16)
 * Rheneas The Gallant Old Engine (Thomas and Friends; Seasons 9-12; became a Gary Stu)
 * Sir Handel The Blue Engine (Thomas and Friends; Seasons 10-16; became an engine who often breaks down and also messes up sometimes, "Sir Handel in Charge" is an example of this)
 * Peter Sam The Green Engine (Thomas and Friends; Seasons 9-16; same as Rheneas)
 * Rusty The Little Diesel (Thomas and Friends; Seasons 9-11; became too bossy to even be helpful like Emily)
 * Belle the Firefighting Engine (Thomas and Friends; Season 15; her personality was wasted in the infamous "Big Belle" episode)
 * Iron 'Arry & Iron Bert (Thomas and Friends: Season 6-onwards; went from villainous and evil diesels to just regular bullies, though they were evil again in one episode of Season 7, but they went back being sadistic bullies, but just really done in a really mean-spirited manner, and in some episodes, they get away with their antics scot-free, in "Middle Engine" for example, they got away with Percy and James being the middle engines, and neither one of them get punished).
 * Salty the Dockside Diesel (Thomas and Friends; Seasons 14-16; became nothing but a troll to the engines).
 * Ren Hoek (Ren and Stimpy: Adult Party Cartoon; same as Optimus Prime)
 * Charlotte (Making Fiends; went from being a very optimistic Naïve Newcomer who tried to see the best in everything and everyone, albeit with a scant sense of logic and a few realistic dislikes every little girl would have, to a virtually indestructible Pollyanna Idiot Houdini)
 * Vendetta (Making Fiends; went from being a narcissistic card-carrying bully with supernatural abilities to a stereotypical villain who abuses the Evil Laugh and whose obsession with clams goes all the way to the name of the town)
 * Ash Ketchum (Pokémon the Series: Sun and Moon; proved that he is annoying and that he will never age; Ho-Oh is still not an excuse!)
 * Son Goku (Dragon Ball GT and Super; became dumber and more manchildish)
 * Chi-Chi (Dragon Ball Z, GT and Super; became an obnoxiously overbearing mother to her sons, Gohan and Goten, to the point where she attempted to take Gohan's infant daughter away from him as she couldn't stand the thought of her becoming a Z-Fighter when she grew up)
 * Broly (Dragon Ball Z: Broly - Second Coming; became a brainless lunatic who did nothing but scream "KAKAROT!" at the top of his lungs)
 * Miho Nosaka (Yu-Gi-Oh! 1998; became a selfish, hypocritical ditz who uncaringly strings Honda around when she clearly has no interest in him and just uses him for her own personal gain)
 * Sakura Haruno (Naruto; became a violent psychopath who attacks Naruto for no reason)
 * Nick Ashby (Kate Ashby/Nick Ashby's Lawful Adventures; went from being a simply strict husband to a "heroic" jerk who kills people)
 * Sheen Estevez (Planet Sheen; Went from being a funny comic relief to an immature, childish and unfunny idiot)
 * Spike (The Tom and Jerry Show; went from being a friend to Jerry to a mean, short-tempered jerk who hates both Tom and Jerry)
 * Tommy Oliver (Power Rangers; became an annoying ranger every season after season)
 * Captain Man and Kid Danger (The Adventures of Kid Danger; became callous, reckless, and bland with no personality. Hey, they're callous enough to give the Teen Titans out of all people a run for their money). Seriously.
 * Manny the Mammoth (Ice Age; became a stereotypical over-caring father in Ice Age 4: Continental Drift and became dumber and dumber as films went on.)
 * Sid the Sloth (Ice Age; Became a stereotypical lazy bum in Ice Age 4: Continental Drift and became dumber and dumber as films went on.)
 * Luke Skywalker (Star Wars; went from an optimistic Jedi who never gave up no matter what to a pessimistic hermit in the eighth film, and due to said pessimism, he taunted and humiliated his nephew (Exactly like how a Sith would do) as opposed to doing something like he did to his father in the sixth film)
 * Chewbacca (Star Wars; became very useless in the seventh film and was never seen mourning for his long-time friend and sidekick, Han Solo)
 * Alex Russo (Seasons 3-4) is changed from an optimistic, confident, charismatic, and yet, an interesting character, to a stereotypical jerk, who screams a lot and always abuses her best friend, Harper, in every episode.
 * Justin Russo (Seasons 3-4) is changed from a voice of reason-type character to a cliched scientist and flat out nerd-type character, who's only there whenever Alex gets too much screen time.
 * Max Russo (Seasons 3-4) is changed from a funny, laid-back, and yet, kind-hearted and dimwitted character with slight intelligence, to an annoying, aggravating, arrogant, jerky, and a too dumb to live-type character, who's only there for comedic purposes only, much like Patrick Star from Seasons 6-8 of SpongeBob SquarePants.
 * Red (Angry Birds Toons Season 2-3) because an overprotective Gary-Stu angry bullylike jerk that likes beating the innocent pigs for fun and leaving them to starve. He is also very racist towards the pigs and is very mean to them for no real reason
 * Chuck (Angry Birds Toons Seasons 2-3) Changed from a lovable, funny speedemon to an annoying idiotic jerk who cares more about looking cool than protecting the eggs, he also gets too much screentime in the newer seasons.
 * Jim, Jake, And Jay, (The Blues From Angry Birds Toons Seasons 2-3) became annoying troublemaking brats that also like to beat the pigs for fun.
 * Matilda (Angry Birds Toons Season 2-3) Became an OCD overprotective Neat Freak that wants everything to be perfect.
 * Bomb (Angry Birds Toons Seasons 2-3) Became a boring penguin with no personality amd eats ice cream for no reason.
 * The Pigs (Angry Birds Toons Seasons 2-3) Became 1 dimensional villain characters who want to steal the eggs from the Birds for no real reason, when they could’ve eaten something else, They also Became punching bags for the Birds.
 * Book (Battle For BFDI; became an unlikable douchebag to Taco)
 * Caillou (Caillou Gets Grounded) became an extremely unlikable, mean-spirited, callous, sociopathic and malicious jerk who takes pleasure in constantly causing trouble for no reason and making his family's and other's lives miserable. True, he was unlikable in the original PBS series because he was very bratty and often threw temper tantrums. However, he was nowhere near as unlikable as he is here. In fact, he is so unlikable in this series that he could give his original PBS counterpart a run for his money. However, his personality can sometimes vary since there is more than one user who makes the videos.
 * Boris and Doris (Caillou Gets Grounded) became cruel and abusive parents towards Caillou who constantly ground him for ridiculously long periods of time for his bad behavior and sometimes even ground him for stupid and nonsensical reasons or even no reason at all. They are especially abusive towards Caillou in the Punishment Day Videos because they give him over-the-top punishments. In fact, they can be just as bad as, if not sometimes even worse than Caillou. However, Doris is shown to be somewhat more caring towards Caillou than Boris. Boris also finds enjoyment of torching his son for fun. They also abuse Caillou instead of punishing him. Doris even defended him on some occasions. Like Caillou, their personalities can sometimes vary since there is more than one user who makes the videos.
 * Rosie (Caillou Gets Grounded) became a huge tattletale, Caillou's punching bag and a Mary Sue, although she is still a likable character compared to Caillou, Boris, Doris and the following two characters in Caillou Gets Grounded, which are Miss Martin and Dora. However, she can have some unlikability at times, such as by contributing to Caillou's over-the-top punishments in some of the Punishment Day Videos. Like Caillou, Boris and Doris, her personality can sometimes vary since there is more than one user who makes the videos.
 * Miss Martin (Caillou Gets Grounded) became a stereotypical mean teacher towards Caillou who treats him in a similar way to how Boris and Doris treat him, except she is not his parent and she does not ground him. Like Caillou, Boris, Doris and Rosie, her personality can sometimes vary since there is more than one user who makes the videos. The only thing about her that's better than her original counterpart is her character design. Still, this does not excuse her flanderized personality.
 * Dora (Caillou Gets Grounded) is the same as Caillou, except she was likable in the original Nick Jr. series and its sequel Dora and Friends: Into the City! Like Caillou, Boris, Doris, Rosie and Miss Martin, her personality can sometimes vary since there is more than one user who makes the videos.
 * Greg Heffley (Diary of a Wimpy Kid: The Long Haul (film)) became an idiot.
 * Frank Heffley (Diary of a Wimpy Kid: The Long Haul (film)) is the same as Greg.
 * Susan Heffley (Diary of a Wimpy Kid: The Long Haul (film)) became a selfish and egotistical mother who belittles her family and bashes modern technology. She can also be an idiot at times like Greg and Frank.
 * Sam Puckett (iCarly Seasons 4-5; Sam & Cat) was flanderized twice. In the earlier seasons of iCarly, she started out as being an aggressive tomboy. During Seasons 4-5, however, she became somewhat less aggressive and more girly. Then, during Sam & Cat, she became a selfish jerk.
 * Cat Valentine (Sam & Cat) became even dumber than she was in Victorious to the point of being an absolute idiot.
 * Sam Wilson/The Falcon (Marvel Comics; became out of character after becoming the "new" Captain America)
 * Mark Taylor (Home Improvement Season 7) became a gothic weirdo.


 * Agent 3 (Splatoon) Started out as the hero you play as that defeated octarains reasonably because they stole the great zapfish, too a heartless racist jerk who attacked agent 8 simply because He/She was an octoling because octolings used to be the bad guys in splatoon, but this octoling heard the Calamari Inkantation and became good and wouldn't attack agent 3, yet, agent 3 still wants to attack agent 8 for the sake of being an "evil" octoling. Thankfully Agent 3 became good in octo expansion because he/she saved agent 8 and Cap'n Cuttlefish from being blended alive and was nice to agent 8 and was self-aware that not all octarians are bad guys
 * Bowser Jr. (Super Mario Bros series) Became an annoying douchy brat

The Overall Reason Why This Trope Sucks

 * Basically, this trope serve as reverse character development, where the characters you either love or hate (gets worse or gets ruined and lose any likability in them).