Hank Pym (aka Ant-Man) has suffered from this perhaps more than any other Marvel character. During a single incident in which he was suffering nervous breakdown and had just completed building a robot programmed to kill all of his his friends, Hank struck his wife, Janet Van Dyne (The Wasp). This immediately had the effect of establishing him in canon both as a wife-beater and severely mentally ill. Dozens of writers over the years have gone back to this time and again, with at least three different stories having been told about the two of them coming to terms with what happened. Hank's remorse is so Flanderized and extreme that he called himself the Wasp when she was thought to be dead.
This carries over even to alternate version of the character. The Ultimate Universe version of Pym was written as a cruel sadist who tortures his wife nearly to death and stole all of his ideas from her.
As of Secret Empire, Hank after having merged with Ultron, finally snaps and calls out the then 'Captain HYDRA' Steve and the AI version for all the stuff that they've pulled which, especially in Tony's case (Steve was morally flipped against his will), makes the incident with Janet, awful as it was, look like a playground scuffle. He has a point, unfortunately.
Sonic's attitude has been cranked Up to Eleven, to the point where he's making wisecracks during a battle with Enerjak, a being with seemingly limitless energy (though this may have been more for comic relief than anything, it was a tad excessive). To be fair, though, it seems to have slightly boosted his badassness—at the cost of emotion (again, though, to be fair, he never really showed much emotion anyway). The part about emotion is slowly being subverted as of #200; ever since Sonic's apparently driven Robotnik totally, droolingly insane, he seems to actually regret having broken down the guy so completely.
An aversion may come from the early comics, which had a much zanier and cartoony format thus exaggerated a lot of the characters' traits compared to their SatAm counterparts, e.g. Sonic existed as a Karmic Trickster with a Totally Radical mannerisms akin to his AoStH counterpart, Sally's somewhat neurotic and no-nonsense attitude was exaggerated into a spoiled, mean-tempered prude and Robotnik was converted into even bigger a bumbling Card-Carrying Villain than his 'Eggman' incarnations. This was reversed as the comic's writing tone became more serious and akin to the show, though some genuine cases of flanderization do pop up on occasion.
Shadow deserves a mention, the calm and pragmatic anti hero he was in games, has increased his pride and lack of hindsight in the comic series. Feels he constantly has to prove himself as the ultimate and gets mocked for his no nonsense attitude due to the comic making light on his serious methods towards threats. He always gets into situations in harsh and reckless ways especially against powerful enemies like Scourge or ADAM biting off more than he can chew. He goes into a roaring rampage of revenge when he loses to those same threats and his pride crushed making him more a sore loser.
Dreadful Musician Cacofonix starts out as at least an average bard - Asterix blows off listening to his music once due to being busy (which annoyed him) and the people sitting near to his performance at the final banquet are cringing with their hands over their ears, but the villagers also perform a plot-important traditional dance to his music with every indication that they are enjoying it. As the comic progresses, other characters (especially Fulliautomatix the blacksmith) start beating him up to prevent him from singing, which develops into a running gag, and he's shown to live in a hut at the top of a tree, where no-one can hear him. By the time Uderzo took over writing, he was so bad that he causes rain whenever he plays, which develops to the point where he ends up being so bad that merely playing a few notes creates an apocalyptic rainstorm that lasts for days.
Bruce Wayne was originally depicted as merely Comfortably Well-Off. Now, he's one of the two richest men in The DCU. Batman himself has become increasingly ultra-competent and infallible in the past few decades. One could argue the flanderization of Batman was necessary to keep him interesting in the context of the Justice League. He's one of the few characters without a true super power, so the question of why they keep him around (aside from maybe his money) needs answering. Having him be the greatest strategist in existence gives him a purpose and even a reason for being one of the guys in charge.
He's also portrayed as the "brooding loner" of the Justice League. This is despite the fact that the "Bat-family" has more members than Superman's friends and allies, two of the five Robins have led the Teen Titans, one of those two also led Young Justice, the other is considered the most trustworthy man in the hero community, and Oracle acts as the Mission Control. He is a close friend of a lot of superheroes as well, and he managed to be something of a father to CassandraCain.
Parodied in Lego DC Comics: Batman Be-leaguered, when he refuses Superman's invitation to join the nascent Justice League. When Alfred asks him about it, he responds with a dramatic rant about how he works alone, only to be interrupted by Robin, Nightwing, and Batgirl slurping the drinks Alfred made for them too loudly.
In 1983, Batman quit the Justice League and created a new team called the Outsiders after Superman saying he would not lead the League in saving Lucius Fox from being a hostage in a far away country for diplomatic reasons, and this lead to a dynamic within the DC Multiverse wherein Batman would be portrayed as a maverick and Superman a boy scout. While they patched things up later that year, 1986's Batman: The Dark Knight Returns (which took place in a possible future) made Batman the ultimate outlaw anti-hero, and Superman a tool for the Ronald Reagan of every political cartoon of the '80s. In the revised DC Universe, DC ran with this dynamic of Superman and Batman being at odds for about a decade before it just kind-of ran out of steam, though the Batman/Superman title and other New 52 material revisited it.
Killer Croc was originally a somewhat intelligent gangster with a medical condition (a very severe medical condition), whose misanthropy was the result of being tormented by everyone (family included) for his freakish appearance. This was eventually downplayed, with Croc becoming more bestial and less intelligent as time went on (this was typically explained that his condition was worsening, further separating him from humanity). By the time of Hush, Croc could probably pass for a bulkier Alternate Company Equivalent of the Lizard (explained away by Hush infecting him with a virus that further increased his mutation).
To a lesser extent, Stephanie Brown started off as a somewhat cynical and troubled girl with low self esteem who was also fairly snarky and a little quirky, but through character development she learnt to let go of her troubles and focus on the positives, but was still constantly facing painful troubles. By the time she became the new Batgirl, though, she became known as 'the fun one' of the Bat family, being full of hope regardless of what the family faces. In a case of Tropes Are Not Bad, most fans generally like this move, and enjoy the fact it makes Steph stand out among the OFTEN troubled and angsty members of the Bat Family.
Similarly, Tim Drake started off as a normal teenager who happened to also be a fairly gifted detective, and was naturally skilled in crime fighting despite being 14. As things went on, he became The Smart Guy of not just the Bat Family, but also the entirety of the teenaged population of the DCU, smart enough to research cloning technology that, while it didn't pan out, was said that he was only a year or so away from successfully cloning Superboy and Impulse according to the Titans Tomorrow story arc (and not just real life 'start as a baby' cloning, but actually recreate them, memories and all). He also became far more nerdy, to the point he's massively neurotic and over-analyses everything. And, inverting Steph, while he started off as a realist, he was also rather idealistic, but slowly his life became so filled with hell that he broke down until he was as broody as Batman himself. Like Steph, many fans likethis aboutTimmy, but a lot of people really don't, as he became popular because he was the most relatable Robin.
The Joker has gone through this. Originally he was just a very wily criminal whose modus operandi was little more than "shits and giggles". Then came the Dark Age of comic books, and all of a sudden the Joker is the Yin to Batman's Yang, with just about every story over the last 20-plus years being about his feud with the Caped Crusader. You'd be hard-pressed to find a story involving the Joker committing a crime that wasn't meant to be an attack on Batman, the one exception being his corruption of Harley Quinn. In the New 52, the Joker's clown aspect has been dropped completely and his characterization can be summed up as "Batman's Arch Nemesis". This was ultimately explained with the revelation that there wasn't one Joker. There were three.
Speaking of which, Harley Quinn. While always a bit ditzy, over time she's become a Genki Girl who's nearly as insane as the Joker. Meanwhile, her attire has become increasingly Stripperiffic to match the Perverse Sexual Lust her fanbase has towards her. It's to the point that works like Gods and Monsters and Batman: White Knight will poke fun at how different the character is from what she started as.
Killer Moth suffered because of this trope. When he first appeared, Killer Moth was more or less the Evil Counterpart of Batman, despite his bright, gaudy costume. An evil criminal mastermind that everyone turned to for help, he was quite the threat. Then Batgirl showed up. They needed someone to show that Batgirl was a worthy addition to the Bat-Family and chose Moth as the target. However, being beaten by an untrained beginner vigilante who only showed up because of sheer circumstance turned Moth into the laughingstock of the Bat-Rogues almost immediately. Suddenly, Killer Moth went from "Batman's equal" to "pathetic nobody". They tried to salvage his character in the 90s by trying to turn him into a From Nobody to Nightmare by transforming him into Charaxes during Underworld Unleashed, but it didn't stick, ultimately being killed by Superboy-Prime in Infinite Crisis. Even other adaptations such as The Batman and LEGO Batman 3 wouldn't be kind to him.
Jim Gordon when he became Batman. So y'know how 90% of the time Jim is okay with vigilantes who don't kill? How he's worked with Batman for years and is actually friendly with him, as well as the other Batfamily members? And how he only frowns on vigilantes who kill or go too far? Well when he's Batman, he hates all vigilantes in Gotham because he's a cop. Heck, "cop" is his defining trait, and actually the only noticeable one aside from the typical "I have to be Batman my own way" shtick that every Batman successor goes through.
Though in Batgirl, he purposefully short-circuited the suit briefly to talk to Batgirl (who he doesn't know is his daughter), and quietly says that he doesn't want to hunt vigilantes down, but it's his job, so it's best if she gets off the streets before he has to chase her down.
While Jason Todd's pre-Flashpoint self used guns as a means to an end, the New 52 and Rebirth version seems to be obsessed with them, flashing them out in every instance, whether he's looking to kill or not. This is usually accompanied by him either narrating that he's using rubber bullets or taking nonlethal shots, or by loudly boasting about all the upgrades he's made to his guns. Furthermore, his grudge against Batman has devolved from opposition to his nonlethal philosophy on fighting crime, to desperately seeking out his approval. As of Rebirth, this attitude has extended towards Nightwing as well.
Booster Gold started as a well-meaning hero whose love of money often got him in over his head. Over the course of the '80s and '90s, writers forgot about the "well-meaning" part and turned him into a money-grubbing jerk. Thankfully, over the course of Infinite Crisis and 52 in the mid-'00s, DC built Booster back up, and now he's a genuine hero again—though the lure of fame and fortune still occasionally tempt him. Even better, he now intentionally acts like that, so no-one except Batman and Superman realises that he's grown into a competent hero in his own right, whilst he roams the timestream protecting history from enemies who — if they ever saw past his foolish reputation and realized he was the one foiling their schemes — would not only kill him but do it in such a way that Booster Gold never existed. So now instead of promoting himself, Booster must do everything in his power to make people think he's an inept idiot, in order to carry out his mission to defend time itself. Even before 52, some writers had started pointing out that there was more to Booster Gold than met the eye. At one point one of the other heroes muses that, being from the future, Booster must have been aware that Doomsday was a monster that was fully capable of killing Superman. And he still stepped up and took the first actual punch Doomsday aimed at a hero on his personal forcefield, to protect another member of the League. Both this acknowledgement and the moment itself hint that some people never completely forgot that Booster was kind of badass.
Donald Duck and Scrooge's portrayal in early Italian-produced comics exaggerated their character traits from the American comic of the time to comical extremes. Donald became a narcoleptic with a complete aversion to any kind of physical work and so dumb he genuinely believed two plus two equaled five point five, who treated his nephews more like slaves than family. Scrooge on the other hand was stunningly violent and cruel towards absolutely everyone, with zero aversions towards outright criminal acts (one story mentioning he made a lot of his fortune from running an opium smuggling cartel), usually getting away with anything and everything purely because he was rich. The characters would eventually morph back into something more closely resembling their America counterparts.
Johnny Storm started off as a somewhat-conceited daredevil hero of the teamnote It's been joked that while the battle cry of the Avengers is "Avengers assemble!", that of the Fantastic Four is arguably "Johnny, wait!". Since the eighties, he's become increasingly more stupid and narcissistic, to the point where he now appears to be a ditzy, Ambiguously Gay metrosexual completely in love with himself.
Reed Richards was originally a tad eccentric and rather emotionally stunted, but was Flanderized in the late 1990s/2000s into a borderline savant who doesn't understand human social behavior. This pretty much is part and parcel of Reed's slow derailment from a many-layered, infamously trope-defying character into a generic scientific supergenius strawman. Perhaps most tellingly, Reed was originally written as a veteran of World War II before Comic-Book Time forced the writers to cut that detail from his backstory. After 40 years of intense Flanderization, though, it's practically unthinkable that the current comics' pencil-necked nerd would have ever even considered serving in the Army, let alone that he would ever have fought in Nazi-occupied France in the Big One.
Inverted with the Thing: in his earliest appearances, he was a complete jerkass who was constantly picking fights with not only Johnny, but Reed, and had no use for people whom he felt were judging him. Later on, he was portrayed as more of a tough guy with a heart of gold.
Subverted with Invisible Woman who was originally called the Invisible Girl, and useless in a fight. She gained the ability to create force-fields, became a more competent fighter, took on the name Invisible Woman (after all, Iceman and Spider-Man were supposed to be teenagers but never referred to as "boys") and has sometimes served as a more competent leader especially during such time as Reed was away.
The Guardians Of The Universe have always been distant and aloof, but were once wise and respected, having created an organization of star-patrolling peacekeepers that has survived for eons. With each passing year though, they become more incompetent, single-minded, and corrupt, lying to their members, holding their own mysterious agendas, and constantly having their mistakes blow up in the faces and inevitably needing to be saved by the Earth Lanterns (and then clearly resenting the aid). One comic even had a Guardian admit he didn't remember why they started the Corp in the first place. By this point, it's a genuine curiosity how they got an organization as advanced and well-functioning as the Green Lanterns working outside of dumb luck. This could be unintentional Fridge Brilliance, as the Guardians are literally as old as the universe itself and long overdue to losing their wits to old age.
Hal Jordan himself has undergone this. He used to be a bit of a hothead who hated authority, but was otherwise a pretty normal guy. These days he's mostly written as a gigantic idiot who flies off into a fight at a moment's notice and bickers with authority no matter what.
The Hulk's raw power has been exaggerated to the point that he might as well just be a Super Saiyan. In his first appearance Hulk was perfectly capable of fluent speech and clear-minded reasoning. Over the years the "dumb" part of Dumb Muscle got amplified along with the "muscle", until we reach the iconic "HULK SMASH!" levels. Then, Peter David got the idea of explaining this as two different facets of Bruce Banner's fractured mind manifesting in different types of Hulk. How his level of strength tends to be inversely proportional to his intelligence has been explained by that his ability to reason tends to put limits to how much pure rage he can build up. An alternate universe supervillain, the Maestro, was even created out of the idea of "what if the Hulk stopped caring about holding back, then lived for a hundred years?"
Contemporary Marvel writers have some fun with this when time-travel shenanigans bring later characters in contact with early Silver Age Hulk. Heroes (and villains) expecting the monosyllabic rage-monster are shocked to meet a gruff, clever Hulk who is functionally equivalent to a stronger, tougher, more devious Ben Grimm.
Iron Man used to be a fairly well-rounded character, being not only a super hero, but also a captain of industry, a millionaire playboy, a bit of a womanizer, a technological genius and - rather uniquely - physically crippled from his inception. He also had a bout with alcoholism. During Civil War, he got flanderized into a stubborn pseudo-fascist who'd just as soon throw his best friends in jail if they did not fall in line with the Super Human Registration Act. He had not nearly recovered from the fan-impact of that when Matt Fraction took him on an entirely different flanderization trip by reducing all his issues to side effects of alcoholism, but at least he made him be sorry for his behaviour during Civil War. Now, it seems Tony Stark spends approximately half the time agonizing about how badly he sucks. His characterization later got better during Kieron Gillen's run as Iron Man took some days off and went to a vacation in space, as has taken a more carefree approach to his life.
Also, like Bruce Wayne in the DCU, Tony Stark seems to have gone from "guy with a few million bucks" to "probably the richest man in the Marvel Universe".
A notable aversion occurs with, of all people, Guy Gardner. Giffen and DeMatteis were concerned with how much Flanderization had already occurred with the character, who initially was more intelligent than Hal Jordan, but by the time of joining the JLI was mostly famous as a Jerk Ass with severe brain damage. A punch from Batman sends Guy into an alternate, hyper-sensitive persona, eventually revealed to be a total con, as Guy enjoyed screwing with his teammates. His girlfriend, Ice, sees through it.
The Justice League in general occasionally suffers this problem. The heroes in their own books have multi-faceted personalities, while Justice League in the hands of sloppy writers reduces them to their most stereotypical natures, such as Batman being completely unfeeling and methodical, or Superman's "boy scout" persona. This is in part because each character was originally The Hero in their own titles. They weren't developed with a group dynamic in mind so some of their key character development has also come from them playing off of each other in the team books.
When the Little Lulu comics first introduced Wilbur Van Snobbe, he was accurately depicted as a JerkassSpoiled Brat who would go out of his way to try to best either Lulu or Tubby, with no success. However, when the anime version was created, the creators took away his snobbish characteristics and turned him into a well-mannered rich boy who served as The Smart Guy to Lulu and the others. Then, when The Little Lulu Show was created, his snobbish personality was fortunately returned intact, just like in the original comics.
Magica DeSpell's obsession with Scrooge McDuck's #1 Dime. Though her introduction does have her focused on attempting to steal it, other Carl Barks stories usually had Magica simply wanting to become rich, and would often have her working on schemes completely unrelated to the dime. Nowadays, she's completely psychotic about that coin, and you rarely, if ever, see a Magica story without it as her prime goal anymore. The dime itself also went through a sort of Flanderization. In the original story with Magica the dime had no initial magic powers. Magica just needed it as a spell component. Later writers seem to have missed this point and decided that the dime was somehow the source of Scrooge's wealth. In some stories, Scrooge can lose the dime over simple theft and suddenly his entire empire is crumbling. Don Rosamocks this in the Grand Finale of The Life and Times of Scrooge McDuck, where the Flanderization extends to rumors in-universe. Scrooge finds the idea that he owes his entire fortune to a lucky charm (which he had for twenty years before he even started to make his fortune!) incredibly insulting. That said, Rosa's take on the characters has also that Magica's spell would indeed work should she get her hands on the coin, and that losing the dime would indeed cause Scrooge to lose such spirit that he'd be no match for his enemies.
In his first appearances in the comics, Grouchy Smurf from The Smurfs was perfectly capable of carrying on a normal conversation, even with his grouchy attitude. Over time, though, his Mad Libs Catch Phrase of "I hate (...)" became more and more prominent in his dialogue, and by the time the cartoon came around, almost all of Grouchy's dialogue was based solely around declaring his hatred for whatever the others were talking about at the time.
The Venom symbiotes that most often show up in connection to Spider-Man have been established as having a vulnerability to fire and sonic attacks. When the latter was first used, it required a sonic emitter built by Reed Richards for this specific purpose. Over time this vulnerability has been exaggerated to the point that any loud noise can repel a symbiote. As for fire, at its worst the mere presence of a single lit lighter has been able to drive a symbiote away.
Starfire of Teen Titans fame was a sexually liberated and emotionally open alien who celebrated free will, expression of love, and monogamous relationships. In Red Hood and the Outlaws, she's a nymphomaniac with no memory or cognition, and is frequently used as titillation.
Originally, Superman was something of a tough guy tackling (literally) wife beaters, war profiteers and abusive orphanages. By the end of the forties, however, he was the leading citizen of Metropolis, battling larger-than-life villains.
Also when he was first introduced, he was a real scrapper and not afraid to get in the face of authority figures. That changed around World War II along with Batman, however by the end of the fifties, he was flanderized into the ultimate boy scout and establishment figure. By the '70s, he'd become somewhat more morally ambiguous and a bit more cynical about people in power.
Supergirl started off as a sweetheart with quite a temper if pushed and a snarky side. Then she got killed and writers and fans got into their heads the notion that she was a saccharine-sweet, ever-smiling girl who never, ever, talked against her cousin (which flies in the face of her character development throughout the Pre-Crisis period). In order to (over)compensate for this, subsequentreboots amped up her hotheadness and hotbloodedness to the point she was turned into a Red Lantern and became "Miss Rage Issues" to the fandom's eyes.
Brainiac 5 from the Legion of Super-Heroes is an utterly brilliant genius with limited social skills. He might be impatient and rude, but he clearly cared for his teammates and people on the whole. Throughout several decades and reboots "may be an obnoxious jerkass sometimes" somehow devolved into "is an unbearable smug jerkass who can hardly stand his own teammates", and modern Legion writers appear to have a hard time remembering he's a hero.
Originally Power Girl had a mischievous side, flirty side. Her New 52 version appeared in Worlds' Finest has little characterization other than "extremely lewd and man-hungry".
Cat Grant was introduced as sort of a Good Bad GirlBroken Bird. Someone who had a bit of an immoral past that she was trying to move beyond, and was looking for a good man like Clark Kent to be her anchor. Nowadays she's portrayed as a Lovable Sex Maniac at best and just Really Gets Around at worst. It's been mentioned that this is a facade Cat is using because of the pain of losing her son so many years ago.
During the earliest stories of his series, Superman's Pal Jimmy Olsen, in spite of being somewhat naive and cocky, was a competent detective and Pintsized Powerhouse who might get a head start on beating up the bad guys before Superman got there and who, if captured, often found some way to alert Superman with or without his signal watch. As the stories progressed, he became more and more The Load.
The Ultimates have been criticized for being an extreme Flanderization of the Avengers. In their initial run, Mark Millar tended to take the most famous aspects of each Avenger — Cap being of the '40s, Tony's hedonism, Pym slapping Janet, Jan being slapped by Pym, Hulk's rage, etc. — and amplified them all several times over: Cap was painfully old-fashioned in speech and social views, Tony was always drinking and/or flirting with some blonde, Pym was a textbook wife-beater, Jan was a textbook battered wife, and Hulk was a murdering cannibal. This went into overdrive when Jeph Loeb took over the third volume. Tony was always in a drunken stupor and Cap spontaneously picked fights over Wanda's choice of attire.
Wonder Woman: Wonder Woman's willingness to kill got this when the New 52 reboot happened. Before she was willing to kill, but only in extreme circumstances where she had literally no other choice. In the New 52, DC cranked this up to ridiculous degrees, with her casually killing villains she fights and actually gloating about doing so to another superhero. This has had the effect of making it hard to believe that she would ever be made part of the Justice League, let alone allowed to continue operating; all of the other heroes retained their beliefs in no-killing or only killing when necessary.
Even his powers became flanderized. At first, the idea behind his "quick healing factor" (note the word "quick") seemed to be that he simply healed faster than normal people. By some point, it was decreed that he could regenerate from a single-celled organism and was basically unkillable and therefore immortal.
Under writer Jason Aaron, another example has occurred. While Logan always had kind of a rivalry with Cyclops, the two are friends and can agree on some things, and Logan does respect Scott. Furthermore, while Logan is a Jerkass, he's willing to admit when he's wrong. Under the aforementioned writer, Logan's Jerkass tendencies have become his dominant trait, with him mouthing off about why Cyke sucks literally every time the two meet, and he outright ignores anything good the guy does.
Surge, whose Jerkass tendencies have been blown way out of proportion. While she was initially depicted as being kind of a Jerk Ass, it's understandable (she was disowned by her father for being a mutant and was a bum who had to take drugs to sort-of control her powers), she was always more of a Jerk with a Heart of Gold and she was always kind to those she considered friends. While she was always an outspoken, rebellious smart ass, her later depictions make her much harder to sympathise with as she has been portrayed as an unrelenting bitch and it has become her most dominant characteristic. She has since entered Comic Book Limbo, though her brief appearance in Avengers Academy had her being more reasonable, and had her revert to her old portrayal of Jerk with a Heart of Gold.
Mojo was introduced in a miniseries as a psychotic Eldritch Abomination obsessed whose very presence actually caused living things to wither and die and who casually committed Mind Rape. He also commissioned genetically-engineered slaves to act in movies to entertain him. Even Doctor Strange feared what would happen if he stayed on Earth for long. As soon as he was brought into the main X-Men comics, the mystical powers and murderous demeanor were downplayed and the media obsession was turned Up to Eleven, so Mojo immediately became a comedic villain used to spoof the entertainment industry. He's still pretty damn horrible, though, and his comedic personality makes it worse when he does something like torturing Nocturne For the Evulz, or cheerfully sending someone to have their spine freaking removed.
Wolverine's daughter/sister/Opposite-Sex Clone, X-23 suffers from much of the same treatment as he does. Once her backstory was revealed, Laura was established as a highly-skilled fighter, and a very intelligent and highly educated young girl with extensive assassin and black ops training, while New X-Men expanded upon this further by revealing her to be a gifted strategist as well. Most writers now completely ignore everything after "highly-skilled fighter," and give her all the subtlety in combat of Leeroy Jenkins. This is most egregious in Avengers Arena, where the writers give lipservice to her training and Awesomeness by Analysis, and still have her decide the best strategy for taking down Apex (who is controlling a Sentinel) is a direct frontal assault. Even the trigger scent has been subject to this. Initially, the conditioning the Facility subjected Laura to resulted in her rages focusing specifically on whatever was marked by the scent. By the time her solo series and Avengers Arena rolled around, the scent was now sending her after everything in sight.
Cyclops has suffered this himself over the years. He was always a little aloof and had some trouble socializing with those around him, he even had trouble telling Jean Grey, the woman he loved, how he felt even after they hooked up, and he was always under a ton of pressure that some times caused him to chew people out, but he was always had the best intentions for those around him and just wanted to keep his friends and loved ones safe as they fought for a better world. And then some very, very, very bad stories happened to him and as time went by more and more writers - and fans - came to see him as just being "that insanely repressed jerk who isn't Wolverine." Some writers do remember to give him positive traits from time to time though.
One of the chief gains of All-New X-Men, which brings the original team of X-Men into the future to stay with time travel, is that Teen Cyclops is a version of the character with both flaws and things working for him instead of a few redeeming qualities that very occasionally shine through an irrationally militant mindset, and who hasn't alienated most of the X-Men to some degree by being a total hardass.
Considering how often Cyclops and Havok end up fighting one another, they sometimes get Flanderized into being locked in an eternal Cain and Abel, being unable to abide one another at the best of times and one of them being a super-villain (usually Havok) at worst. This portrayal appears in the Ultimate, Legends, and Misfits universes, where (unlike their 616 counterparts) they don't need the influence of any psychic brainwashing to bait them into fighting.
A number of writers sadly only ever saw Jean Grey as either the Phoenix or "that cute girl Cyclops and Wolverine fight over." Jean Grey's reputation as the person who resurrects frequently has been further exaggerated, with Phoenix – Endsong demonstrating multiple deaths and resurrections over a few pages, further lampshaded in Deadly Genesis, when Scott and Logan react to the possibility of her resurrection in the same panel. In X-Men vol 4, the possibility of Jean Grey resurrecting was further discussed when her DNA became a plot point in the creation of a host for Madelyne Pryor.
Mr. Sinister is an interesting case. Originally introduced by Chris Claremont as something of an evil cipher, little was known about Sinister other than that he was a Mad Scientist and that he was obsessed with Cyclops for some reason. Claremont had originally planned for a long, drawn-out reveal (in his usual style) that would have established Sinister as an 8 year old boy with the mutant power of aging very, very slowly — as in, he was already over 100 years old when he was in the orphanage with Scott despite his body still being 8 — using the Sinister persona as a front. Claremont's abrupt departure shelved this plan, and so a new origin story was created for Sinister, one in which he was a scientist from Victorian England granted power and immortality by perennial X-Men Big BadApocalypse.. This new origin story portrayed him as something of a Tragic Villain, and most of the stories of the time followed suit to greater or lesser degrees. But beginning with 2002's Weapon X a new interpretation for Sinister was introduced, one which hewed closer to the Claremontian Mad Scientist but also cranked his evil quotient Up to Eleven by making him an Expy of infamous Nazi scientist Josef Mengele. Since that time Sinister's become increasingly more affiliated with the Nazi regime, increasingly more Nazi-like in general, and increasingly more prone to playing the Politically Incorrect Villain.
The Doctor Who (Titan) Eleventh Doctor comics depict the Master's TARDIS as always being a white classical column, to the point that the Doctor recognises it in a companion's visions and as a symbol on a flag. In fact, the Master's TARDIS only assumed that form on TV in the later episodes of "Logopolis" and the first episode of the next story "Castrovalva". However, the white column form had already been taken as the definitive one, for some reason, in Fanon, especially among Sexy/Lolita shippers. (Yes, itexists.)
Tintin: the Dupont's, (Thomson's in the English version) while still subject to quite a bit of slapstick they where also shown to be quite competent in their earlier appearances (including successfully busting Tintin out of jail at one point, if only so they could arrest him themselves). Their competence slowly started decreasing as the comics went along though, while their Comic Relief status was played up more and more, going as far that you actually wonder how the hell they still have their jobs in later albums.
Lucky Luke: Jolly jumper, while capable of some impressive feats, was actually just a normal horse during the early comics and drawn as such◊. His intelligence got more and more played up once René Goscinny took over the writing, eventually leading to him being given a much more cartoony◊ look, capable of Animal speech and feats no normal horse should be capable of.