Character derailment

Character derailment is the opposite of mh:greatcharacters:character development. Instead of learning from mistakes, these characters just get worse.

It is not to be confused with flanderization, as flanderization involves over-exaggerating and amplifying a character's traits to the point that it goes too far. Character derailment, on the other hand, refers to a character's traits (flanderized or not) becoming vastly different compared to what was previously shown.

Why It's a Derailment

 * 1) Alongside the negative aspects of Flanderization, this makes characters who're once liked, loved, and/or adored, become a lot more unlikeable or hard to tolerate than how they started off.
 * 2) This trope often makes the character become poorly written on top of being unlikable due to having a lack of balance between their flaws and what makes them redeemable/likable.
 * 3) Changing up the personalities of what made the character(s) originally used to be in an improper fashion tends to be executed badly by making them too out-of-character for their own good.
 * 4) It often shreds apart the personality and charm of the characters, making them one-dimensional in the process.

Redeeming Qualities

 * 1) When characters are given proper character development, it makes them sympathetic and likable. They can also improve with rerailments.
 * 2) There are many instances when changing up the personalities of a character can be done in good light. Where it can potentially make them more entertaining to watch, this is better shown in the good aspects of flanderizing a character. The category Category:Dynamic characters on GCW can be potentially considered to be the good side of both; Flanderization and this trope to an extent.
 * 3) * Three examples of these include Homer Simpson from The Simpsons during Seasons 1 to 10; where he was originally a brash, good-hearted father who was a little clumsy as of Season 3 and Season 4-7 has made him into a more of a well-written dingbat that made him more hilarious, lovable and entertaining than before, Hugh Neutron from The Adventures of Jimmy Neutron; in the original movie, he was intelligent if a goofy father and the show has made him more of a lovably weird manchild whose also idiotic and hilarious in a well-written fashion, and finally, mh:greatcharacters:Earthworm Jim from the animated series with the same name; in the original games, he was a goofy yet diligent hero who is prone to the game's comedic moments despite being competent, the animated series made him more of an incompetent and childish goofball with a hammy dialect who's also enjoyably spunky, boisterous, talented, heroic and unpredictable.
 * 4) There are viewers who can still enjoy these characters and find them entertaining despite their derailment.

Notable Characters Who Suffered Character Derailment

 * Fonzie (Happy Days; Season 4-11; He is the trope namer for jumping the shark, which he literally did in the episode "Hollywood Part 3". This is character derailment because in season 2 he got hurt for a horrible reason)
 * Skarloey (Thomas and Friends; During seasons 9-12, he acts like a child. Thankfully, in the movie "Blue Mountain Mystery", he is back to being portrayed as an old grandpa.)
 * SwaySway and Buhdeuce (As the series went on, they began to treat each other like crap, especially in "Wolf Head Bread" and "Unlucky Duckies")
 * The Titans (Teen Titans Go!; Becoming manchildish goofball shells of their former shelves, with the slight exception of Raven)
 * The Powerpuff Girls (2016; SImilar to TTG, becoming childish and annoying shells of their former selves)
 * Henry Danger (Becoming more and more of a jerk in the first 3 seasons, but got a rerailment as of Season 4)
 * Ray Manchester/Captain Man (Henry Danger; Became more and more of a reckless jerk in the first 3 seasons, but got a rerailment as of Season 4)
 * Charlotte Page (Henry Danger)
 * Jasper Dunlop (Henry Danger)
 * Piper Hart (Henry Danger)
 * Danger Mouse (2015)
 * Sasuke Uchiha (Naruto Shippuden)
 * Madara Uchiha (Naruto)
 * Yuuki Terumi (BlazBlue series)
 * Nana (Elfen Lied)
 * Son Goku (Manga only)
 * Dongtae (DICE: The Dice That Changes Everything; Season 4)
 * Aya Asagiri (Magical Girl Site; second half-became a muted girl after Yatsumura lost her lifespan and vanished)
 * The Thunderman Family
 * Thomas the Tank Engine (Sharon Miller era)
 * Dawn Harper (Nicky, Ricky, Dicky, & Dawn)
 * Daffy Duck (DePatie Freleng/Seven-Arts Era) (Becoming more of a ruthless psychopath that resembles a off-putting version of Yosemite Sam)
 * SpongeBob SquarePants (seasons 6b & 7) (Became more of a obliviously joyful manchild than ever).
 * Patrick Star (seasons 6-9a) (Becoming an reckless sociopath and a bigger jerk to SpongeBob)
 * Mr. Krabs (Becoming more of a villain than a anti-hero)
 * Cosmo Cosma (seasons 9 & 10) (Becoming "comedic" protagonists with extremely shrill voices)
 * Blooregard Q. Kazoo (Foster’s Home for Imaginary Friends; seasons 2-6) (Becoming the show's "Flanderized Patrick Star" in a more extreme way)
 * (He had shades of this in season 3, one moment being the episode "Carl Wheezer, Boy Genius", but he was still a decent character despite this)
 * (Became much less intelligent in the TV show than in the movie, at least he is a very redeemable version of the typical "dumb dad".)
 * Sheen Estevez (Planet Sheen) (Becoming a very irreverent, blaze idiot who doesn't care about returning to Earth.)
 * Seymour Skinner (seasons 9-30)
 * Homer Simpson (seasons 11-30) (Becoming more of a jerk than ever before)
 * Marge Simpson (seasons 16-30) (Becoming more of a nagger and more of a killjoy)
 * Bart Simpson (seasons 16-30) (Becoming more and more of a psychopath who enjoys torturing his father)
 * Lisa Simpson (seasons 7-30) (Becoming too much of a smart-aleck with a superiority complex)
 * Ned Flanders (seasons 11-31) (Becoming the pure definition and trope namer of the term: Flanderization.)
 * Peter Griffin (season 8-present) (Becoming a complete sociopath who ruins the lives of others and doesn't care about the murderous actions he causes, with a hateful streak).
 * Lois Griffin (season 8-present) (Becoming as much of a subpar parent and more of a degenerate)
 * Brian Griffin (season 8-present) (Becoming a polictical soapbox and more of a ruthless jerk to Stewie)
 * Roger Smith (season 8-present) (Ever since season 8's "Love, AD Style", Roger has become a massive sociopath)
 * Stan Smith (season 10-present) (Became more of a horrible father and husband to the point where he had Francine sent to an insane asylum just because he forgot his wife's anniversary.
 * Francine Smith (season 10-13) She became a more neglectful mother and almost a full Lois Griffin clone, but not as bad.
 * Rosalina (SuperMarioLogan) (Becoming more of a idiot and less of a nice person to Mario)
 * Mr. Goodman (late-2016-present) (Becoming a ruthless businessmen who antagonizes Mario for money)
 * Discord (My Little Pony: Friendship is Magic; season 9) He had a chance of becoming a good guy, until it was revealed that he was Grogar all along. He then put the whole world in danger as he made the terrible trio so powerful that even he couldn't deal with them, which just goes against his whole development)
 * Stella (Winx Club; seasons 5-9; Her childishness got much worse, with her throwing actual fits over not getting her way.
 * Diaspro (Winx Club; seasons 3-9; Was derailed into a Miss "Jerkass Yandere" who eagerly brainwashed Sky in order to marry him and tried to kill Bloom. She was also made a Karma Houdini because she wasn't punished for what she had done at Domino)
 * Tecna (Winx Club; seasons 5-9; Losing a lot of the development she got in seasons 1-4)
 * Chloe Bourgeois (Miraculous Ladybug; season 3-present)
 * Eddy (season 5 & 6; Becoming a bigger jerk to Ed and Edd than ever before)
 * Ed (seasons 5 & 6; Becoming too much of a overly emotional, mindless idiot who doesn't know any better, and sometimes becomes a punching bag)
 * Sarah (Ed, Edd, n Eddy; seasons 5-6)
 * Jimmy (Ed, Edd, n Eddy; seasons 2-6; Became more of a crybaby.)
 * Kevin (Ed, Edd, n Eddy; seasons 5-6)
 * Rolf (Ed, Edd, n Eddy; seasons 5-6)
 * Johnny 2x4 (Ed, Edd, n Eddy; seasons 5-6)
 * Lee Kanker (Ed, Edd, n Eddy; seasons 5-6)
 * Marie Kanker (Ed, Edd, n Eddy; seasons 5-6)
 * Numbah Four (Codename: Kids Next Door)
 * Hot Shot (Transformers: Cybertron)
 * Gumball Watterson (seasons 2, 5-present; Went from a naïve, good-hearted, and friendly protagonist into a really big cynical jerk in season 2, his jerkish behavior is toned down in the recent episodes though)
 * Danny Phantom (season 3)
 * Inferno/Roadblock (Transformers Energon season 3?)
 * Bumblebee (Transformers: Robots in Disguise 2015)
 * Ellie (The Last of Us Part II)
 * Lynn Loud Jr
 * Light Yagami (Death Note)
 * Suzaku Kururugi (Code Geass)
 * Nino Arizugawa (Anonymous Noise; Had been forming a relationship with Yuzu (even being kissed by him very often), only for her to turn him down and go back together with Momo.)
 * Sindel (Mortal Kombat 11)
 * Waldek Kiepski (Świat Według Kiepskich)
 * Jin Kazama (Tekken 6)
 * All of the main characters (Game Shakers)
 * Johnny Test (2005; usually seen as selfish, disrespectful, immature, gross, and narcissistic. While he was slightly tolerable in the first season, he got flanderized by the second season and started to mess up his sisters' inventions for his own self-serving purposes, which resulted in him causing trouble for himself and the whole city.)
 * Lincoln Loud (season 4 & 5; he did very stupid and selfish things in those seasons.)
 * Gelatin (Battle for BFDI; While he has always been impulsive to some extent, this is cranked up to 10 in this season where he makes mistakes and acts reckless even more often.)
 * Firey (Battle for BFDI; Went from being the main protagonist of BFDI to a selfish jerk who only cares about himself and his own reputation.)
 * Four (Battle For BFDI; Almost to the highest degree possible. He was once a caring number in XFOHV and 9 years later became a selfish, sociopathic jerk who abuses nearly everyone and everything around them.)
 * Memetchi (Tamagotchi! season 1b)
 * Bella Swan (Twilight)
 * Any character from Sunny Bunnies (season 4-present)
 * Courtney (Total Drama)
 * Mike (Total Drama All-Stars)
 * Zoey (Total Drama All-Stars)
 * Duncan (Total Drama)
 * Sky (Total Drama Pahkitew Island)
 * Dave (Total Drama Pahkitew Island)
 * Gwen (Total Drama)
 * Jaden Yuki (Yu-Gi-Oh! GX, season 4; althrough he's still likable, he suffered from massive PTSD in the arc as he became very brooding and cynical and lost his enjoyment in having fun in dueling)
 * Sonic the Hedgehog (Sonic Free Riders - Team Sonic Racing; Sonic Colors Ultimate)
 * Jet the Hawk (Sonic Free Riders)
 * Wave the Swallow (Sonic Free Riders; She had shades of this in this game since she went from a sly, sassy and responsible tech wizard of the Babylon Rogues in the first two Sonic Riders games to another butt-monkey who's also Team Babylon's scapegoat. But was still a decent character since she was mostly one of the least unlikeable (or at least most tolerable) characters in this game for the most part.)
 * (TV series; became goofier and more incompetent, all in a good way. However, despite this, his creators Doug TenNapel and David Perry both disliked this change of his character in comparison to the public's view of Jim.)
 * Mushu (Mulan 2)
 * Franklin The Turtle (later episodes of Franklin and Franklin and Friends; He is less bratty in the later episodes than he was in earlier ones.)
 * Blinky, Clyde and Pinky (1982 TV series; Specifically Blinky and Clyde swapped personalities, as the former became the coward with a lack of self-esteem and the latter the grumpy determined leader, and finally, Pinky went from a cunning female to a male "more brawns than brains" ghost)
 * Lord Betrayus (Pac-Man and the Ghostly Adventures; Treated more like an annoying comic-relief nuisance than a threatening villain)
 * Mizuki Himeji (Baka and Test: Summon the Beasts; The second season where she was reduced to a yandere who does nothing but torture Akihisa as she and Minami make Akihisa's life a living hell to the point where she actually becomes a nuisance and a disgrace to Akihisa.)
 * The Cockroaches (Oggy and the Cockroaches, Seasons 4-5; in these seasons the episodes were heavily skewed in Oggy's favor, resulting in a two-seasons-long butt-monkey treatment for the former, especially Joey.)
 * Marky (Oggy and the Cockroaches, Seasons 3-4; He lost his suitor trait and here he is just Joey's second bumbling and clumsy follower next to Dee Dee, with the exception of him having a smaller appetite and, somehow, behaving with more or less common sense, depending on the episode. Thankfully, he came back to his original personality in Season 5, while still retaining the cheerful and laid-back aspect he got from these seasons.)