Rob from The Amazing World of Gumball has an inability to communicate as his flaw. He kidnaps Banana Joe's mother so she can paint the future, and attempts to brainwash his former classmates to escape to an unknown place. This gets him beat up by a T. rex.
Vi tends to be impulsive and short-tempered, too often acting without a plan. In Act 1, she leads the kids on a big heist without telling Vander what they're up to, leading to the events of the present. In Act 2, Vi instantly gets into a fight with Sevika upon seeing her; while she almost wins, learning what happened to her sister gets her stabbed, requiring saving by Caitlyn. Vi complains that Sevika got away and will be telling Silco that they're here, but Caitlyn bluntly points out she's the one who exposed herself first. In Act 3, she pushes Caitlyn away and ignores Jayce's warning that she won't make it alone. Vi shows up at The Last Drop and barely survives defeating Sevika again, resulting in both her and Caitlyn being kidnapped, which directly leads to the events of the ending.
Silco has two:
His fatherly love for Jinx. Silco's perhaps greatest virtue simultaneously serves as a source of many of his problems. When Silco defeats Vander and takes his place as the leader of the Underground there is nothing to stop him from achieving his goals. The unthinkable happens when he finds Jinx and instead of getting rid of her sympathizes with her situation, taking her with him. Over the course of the next several years they form a genuine father-daughter bond. But while Jinx grew up to be a capable individual, her mental traumas made her behaviour too unstable and uncontrollable, leading to many obstacles to Silco's cause. He fully realised that but his attachment to his daughter as well as his undying faith in her were stronger as he continued to shield her from those who berate her. Later on, when Silco is offered everything he's ever dreamed and worked for, he's unable to accept it, if it means to give Jinx up. He loses his life while trying to protect his daughter from Vi, who's causing Jinx's mental breakdown, and Jinx accidently shoots him in a frenzy. Even when dying, Silco refuses to blame her for it.
And not mutually exclusive, Projection. Silco may well love Jinx, but he's also fundamentally incapable of truly understanding her because of his inability to not project his own baggage of his relationship with Vander onto her relationship with Vi. This, as much as anything, leads directly to his death as he doesn't realize that while he was perfectly willing to kill Vander in the end, Jinx wouldn't be willing to just allow him to kill Vi, even if he was doing it for what he believed to be, her own good.
Iroh's bizarre Fatal Flaw is his love of tea. While normally the wisest and most sensible figure in the entire series, he makes some monumental mistakes when around the stuff. Once, when having to hide his identity as a Fire Bender, he used his bending to heat up some cold tea and nearly blew his cover. Earlier than that, when finding a plant whose leaves were either the world's most refreshing tea or pure poison, he ground it up and drank it due to temptation. It was poison.
Princess Azula is another example, as she's a psychopath with Control Freak, perfectionist, and paranoiac tendencies. She simply sees people as objects — she manipulates them and expects them to behave accordingly. But she can't handle not being in control of everything. Her belief that people can be controlled through fear flew in her face, and her determination to prove herself to her father, mainly because she believed that her mother only cared for Zuko, proved to be a serious issue that led to a Villainous Breakdown at the end of the series. And when Mai and Ty Lee, the people she thought she had the most control over, turn against her, the shell cracks off the nut, and her relatively subdued madness comes to the forefront and turns into full-blown paranoia, leading her to banish everyone around her for imagined slights and plots against her. Finally, when there's no one around for her to control, whatever remaining sanity she had is whittled to the point that she's reduced to total lunacy and Ax Craziness.
Aang's flaw is his conviction. He was raised as a dedicated pacifist, and though he will fight if necessary, he won't kill. When his opponent is the Big Bad who descended from the man who slaughtered Aang's people with the intent of continuing such a legacy and oppresses the populace of two nations, this turns out to be a bad thing. He finds a solution in the end: de-power the Big Bad.
Katara is known to hold grudges to the point where she could kill someone, especially if she was betrayed or if her loved ones are put in danger. When she runs into Jet after he had betrayed her trust, she immediately attacked him. She flat out told Zuko after he joined the gang that if she thinks he might hurt Aang, she would personally kill him. And when she confronted the man whom she believed killed her mother, she bloodbended him.
Most members of the New Team Avatar has one: Korra nearly gets killed or depowered on several occasions by her aggressive and proud nature. She gets better, at least. Bolin, meanwhile, repeatedly gets himself into trouble through his trusting nature which stemmed from Mako's overprotective nature. Mako's inability to spit anything out or relax for four seconds never gets him into any worse trouble than a difficult breakup. Lin Beifong has trouble letting go of old resentments that she ends up hurting others who aren't even part of her resentment like her niece Opal, not so dissimilar to Katara as mentioned above. Tenzin can be surprisingly naïve for a middle-aged man and has to learn not to compare himself to his father.
Fittingly for a Satanic Archetype, Vaatu's flaw is his Pride — more specifically, his belief that mere humans could never pose a threat to a supremely powerful spirit such as himself.
Raava, Vaatu's Good Counterpart, suffered from a similar flaw as he did. When battling Vaatu, she dismissively told Wan not the meddle in their affairs, whereas Vaatu was smart enough to manipulate Wan into helping him. While she chided Wan for his mistake, she also contributed to that said mistake as well due to her dismissive nature preventing her to explain to the first Avatar why freeing Vaatu was a bad thing, which enabled the God of Evil to manipulate him.
When the Unexpected Inheritance he got from a deceased rival turned out to be fake, Joker was enraged. Plus, King Barlowe knew Joker would binge-spend on the fortune and get a visit from the IRS, at which point the clown will either get jailed for tax evasion or admit he was conned by a dead man (which he won't do as it would turn him into the Butt-Monkey of Gotham).
Another is when he was booted out of a comedy show and got back at the ones responsible by hypnotizing them into becoming supervillains in order to cement himself as the "funniest man in all of Gotham", only to end a laughing stock afterwards.
When his moll Harley managed to successfully capture Batman so that she and the Joker can truly live together, the clown instead pushed her out of a window to her possible death. It was revealed that Batman duped Harley into doing it because he knew that the clown's ego would never allow someone else to kill Batman.
In Big Hero 6: The Series, Obake's flaw is his inability to recognize that just because you can do something doesn't mean you should. Granville's lack of supervision combined with his brain damage has driven him to complete his goals, no matter how dangerous or who gets hurt in the process.
Bob Belcher from Bob's Burgers gets obsessed when it comes to one-upping his rival from across the street, Jimmy Pesto. Oftentimes, in episodes featuring Jimmy, Bob's constant need to beat him causes him to do something that ends up putting him or his family in a worse position. One example is in ''Bob's Burgers S7E21 "Paraders of the Lost Float"", where Bob and Jimmy are in competing floats in a parade float contest. The two floats first try to sabotage each other, causing their decorations to fall off, then try to race one another to arrive at the judge's table first and bribe the judges into giving them the prize. Bob tries to take a detour to beat Jimmy's float but just ends up getting him and his family lost in town.
Codename: Kids Next Door: Chad Dickson's fatal flaw is his Pride. He is obsessed with being the best, even at the detriment of the organization he loves so much. Part of why his Fake Defector act was so convincing is because the idea that he wouldn't want someone tarnishing his legacy after he was decommissioned wouldn't really be out of character for him. Eventually, when he's denied the honor of being Earth's representative for the Galactic Kids Next Door, he undergoes a slow burn of a Villainous Breakdown, exacerbated by being forced into a Chained Heat situation with the person who (unknowingly) took that honor from him, Nigel Uno/Numbuh 1, the main protagonist of the series. Not helping things is that Nigel is completely unaware of his Fake Defector status and thus is extremely belligerent towards him. Eventually, the situation deteriorates and all the pent-up resentment culminates in a Duel to the Death between them, which Chad loses. Ultimately, Chad's flaw results in his and Nigel's broken friendship being completely unsalvageable even with the truth about him revealed.
Danny has two: His darkness, which manifests into him constantly abusing his powers which if he isn't careful, would result in a Bad Future. The other is his emotions which he has a hard time containing — the latter is often used to his advantage by some of his baddies. Unlike the first example, this is one he has yet to resolve since at the end of the day he's still a Hormone-Addled Teenager.
In Darkwing Duck, Darkwing's massive It's All About Me attitude and his need to constantly hog the spotlight land him in plenty of trouble. He always has to make a dramatic entrance, takes great pains to ensure the world is well aware of who he is, and will throw a huge fit anytime another superhero (especially Gizmoduck) comes out to help. All of this gives the villain the chance to get away clean, or worse, win outright. He does realize he made a huge mistake, but it never sticks.
Lord Viren is single minded with using Cutting the Knot answers when faced with problems. His desire to find "practical" (read: expedient) solutions even at the cost of people's lives and to take shortcuts to get what he wants without considering the consequences has put him at odds with Harrow and other members of the court like Opali and Amaya, who intensely distrust him. Said desire feeds into his second Fatal Flaw - Didn't Think This Through. Viren rarely - if ever - considers the consequences of said "solutions," which leads to them eventually causing more problems than they solve. After season 5 he is forced to comfront these consequences when his daughter Claudia begins to emulate his worse traits with even greater zeal.
Claudia has abandonment issues (stemming from her mother walking out on her father and demanding her choose between the two) and is willing to do quite literally anything to keep her family together. Given that her father is Lord Viren (above), this leads to her doing a lot of very dubious things for him, even when her brother bails as he realizes Viren's going off the deep end. Her obsessive loyalty even goes too far for Viren himself when she resurrects him with dark magic and he has a Heel Realization. He ends up letting himself die when the spell expires, which doesn't really help her mental problems all that much.
Impatience is Prince Karim's biggest flaw. His wish to see the Sunfire Elves regain their prosperity sooner, rather than later as Janai would have it (in accordance with the gradual return of the power of their magic over generations), leads him to try and seize the throne by force before his allies can consolidate, causing them to turn against him when he loses his honor duel with Janai.
The most obvious Fatal Flaw is Eddy's Greed. Much of the driving force in many episodes is Eddy trying to scam other kids out of their money so he can get his hands on jawbreakers (or just keep it for himself). Many of Eddy's schemes could be legitimate business ventures if he applied himself. The trouble is that Eddy's obsession with making as much money as possible keeps ensuring that Failure Is the Only Option for him. There is also his impulsiveness — when he wants something, he wants it right now and will chase after it with little regard for the consequences.
Double D's spinelessness means that he's often dragged or goes along with Eddy and Ed's shenanigans whether he wants to or not. His inability to assert himself with his friends or the neighborhood kids often results in him being punished alongside Eddy and Ed, even the few times when he's completely innocent and/or tried to stop the other two. He also has a bad habit of letting his reputation of the smartest kid in the cul-de-sac go to his head at times and he has to be right about everything, making him quite inflexible and not good at bouncing back when things backfire on him.
Ed's stupidity is his flaw since he is very gullible and prone to making mistakes. He often doesn't understand what's going on, meaning that more short-tempered characters like Eddy or Sarah take their anger out on him or him getting manipulated easily.
Sarah's is Wrath. There is rarely an episode where she isn't either yelling at someone or beating them up; the other kids in the cul-de-sac rarely help her as a result.
Kevin's is Pride, being an arrogant Jerk Jock who likes to think he's the coolest guy around.
The KankerSisters, who all fall under Lust, as their habit of subjecting the Eds to unwanted kisses and affection actually just terrifies them and drives them further away.
Jimmy's childishness makes him an easy target for bullies (especially when Sarah isn't around). He is often dismissed and patronized even when he does have legitimate concerns or opinions.
One of the strongest examples is Demona and her refusal to take responsibility and accountability for her actions. After all Demona was the reason why her Gargoyle clan was destroyed by the Vikings and why the surviving clan members got cursed, which is the genesis of the series.
Goliath's flaw is his anger and need for revenge, especially if someone in his clan is hurt. Such as in ''Deadly Force" when he mistakenly believed that Elisa was nearly killed by the gangster Dracon and Goliath ruthlessly hunted him down and in "Hunter's Moon", his desire to kill the ones who almost killed his daughter Angela overruled his common sense.
Every single Pines family member in Gravity Falls has at least one critical flaw that tends to kickstart the conflict of the stories:
Dipper Pines's flaw is his insecurity; Dipper has done some very stupid and very dangerous things in an effort to prove himself, such as reciting a curse out loud in an attempt to be taken seriously by federal agents. In addition, these insecurities have given Dipper something of a defeatist mentality, which impairs his ability to fight back in difficult circumstances.
For Mabel Pines, her selfishness meant that she often never considers what everyone else wants and instead, prefers that they do what she wanted to do. She is also shown to be quite insensitive to Dipper's feelings as despite the fact that she knows that Dipper is troubled, she still constantly picks on him. This flaw is what ultimately caused a rift between the two and allowed Bill to exploit her emotional state in order to directly cause Weirdmageddon.
"Grunkle" Stan Pines has three; First, his issues with trusting and confiding in others, which comes back to bite him in Not What He Seems. Second, his temper, which cost Ford his dream scholarship and almost doomed the entire world when Ford corrected his grammar, prompting Stan to attack him, thus breaking up a magic circle that would have destroyed Bill. Third, similar to Mabel, is his selfishness and his obliviousness to it. Part of the reason he and Ford had a falling out was Stan assuming that the latter would be comfortable with not going to his dream college and feeling threatened when he realized Ford was seriously thinking about it.
The Author (aka Stanford Pines) lets his obsession with his own work and science drive away everyone he cares about, including his brother and Fiddleford. He is also really bad at just explaining things, usually due to trust issues or lack of communication skills. Among other things this leads to his assistant leaving and going mad, a fight with his brother that gets him sucked into another dimension for about thirty years, only trusting one person with world-saving secrets, and being part of a chain of events that kicks off Weirdmageddon. Adding to his poor communication, he assumes that the people in his life won’t be emotionally affected by his choices, both assuming that Stan would be fine with him going to West Coast Tech instead of sailing around the world together and that Mabel would be fine with Dipper staying in Gravity Falls as his apprentice instead of going home to Piedmont with her. They weren’t.
He also has a breathtaking ability to hold grudges for literal decades, as shown by his treatment of Stan.
Two common flaws for all of the Northwests is both Snobbery and Greed. Nathaniel Northwest convinced the local lumberjacks to build his mansion in exchange for an annual party. After it was finished, the Northwests literally shut the gate in their faces. This escalated into the death of a lumberjack and cursing the family for 200 years. His descendant Preston is even worse when he tries to join up with Bill during Weirdmageddon. Only Pacifica was able to break out.
Gideon’s is Obsession. He’s determined to be with Mabel, despite the fact that she doesn’t want anything to do with him. It’s not until the Grand Finale that it sinks in that she doesn’t love him. In addition, When he found out that Journal 1 was missing, he chased Dipper and Mabel to get it, despite the fact that he’d won at that point: he had the Shack, Waddles, and two of the journals. This resulted in the twins and Stan defeating him and being sent to prison.
Like Dipper, Robbie also has insecurity. He was genuinely threatened by Dipper’s crush on Wendy despite it obviously being a Precocious Crush to the point where he was willing to fight Dipper. He’s also implied to be nervous about his skill as a musician, ripping off a song in order to win Wendy back. Unfortunately, it also brainwashed her, which resulted in her dumping him.
The Grim Adventures of Billy & Mandy: Grim describes Jack as having once been a pleasant fellow and harmless prankster. The problem was he didn't know when to stop pranking people. And as his tricks escalated in severity, the townsfolk finally had enough and orchestrated his death.
Krass has fear of abandonment. Krass lost her parents in a crash and was deeply traumatized by it. After the crash, she was adopted into the Tiger Tribe and raised alongside Adam. All of her arguments with Adam over their roles as Masters of the Universe stem from her fear that Adam will leave the Tiger Tribe, leave her, for another life. Skeletor preys on this fear and eventually convinces Krass that the Masters of the Universe have abandoned her for their new place in the royal court of Eternos. And by promising to bring her lost parents Back from the Dead, Skeletor succeeds in turning Krass to the power of Havoc.
Duncan has a bad habit of acting without thinking things through. When Duncan's working on a problem, he just charges ahead with what he thinks is the solution without taking a moment to examine the situation and realize any flaw in his plan.
When Adam, Teela, and Krass are Buried Alive, Duncan figures out how to remotely activate the thrusters of his ship buried with them to clear away the rocks. Cringer has to physically keep Duncan from starting the ignition to remind him to warn the others of the plan so they can get clear of the blast radius.
When working to repair a damaged RK drone, Duncan uses the first data cog he finds to fix the damage without looking at anything else held in the chest with the cog. Had he read the included book, he would have known the cog held all the knowledge and memories of a great magician which made the robot think it was that magician.
Helga Pataki's primary flaw is insecurity. She is unable to be her true, kind, articulate, and intelligent self due to her fear of being shunned by others, so she resorts to being The Bully instead. Arnold would likely return her affections if she were to stop treating him like garbage and be herself. If she were to try harder in school, her neglectful parents would probably pay more attention to her (but as we've seen with her older sister, Olga, that might not be a good thing). and while she might get a few snickers from Harold or the others, she would be in a much better place and would be happier for it. Her nanny Inga in "Helga and the Nanny" even tells her that she's doomed to suffer as long as she continues to push others away.
It's not addressed much but Phoebe has a bad habit of going Drunk with Power whenever she's given any kind of authority and several of her A Day in the Limelight episodes show her going completely overboard, particularly the episode she's made hall monitor or in "Phoebe Breaks A Leg."
Rhonda's is her snobbery, as even though she is a kind person at heart, her Alpha Bitch behaviour means that whenever she gets knocked down a peg, people are rarely sympathetic towards her and she struggles to relate to her peers or cope without her wealth and popularity to fall back on, such as "Rhonda's Glasses" or "Rhonda Goes Broke."
Infinity Train is built around this. Each season focuses on a new passenger of the eponymous train, who can only leave when they've resolved a notable personality flaw.
Season 1 has Tulip. Her issue is a general unwillingness to work through her feelings, preferring to bury them rather than accept imperfection and move on.
Season 3 has Grace and Simon. Grace's pride is what led to her starting the Apex to begin with because she couldn't own up to the fact that she didn't actually know what the numbers meant, and only wanted recognition. Meanwhile, Simon's obsessive nature means that once he gets an idea into his head, nothing will convince him to reexamine it or consider he may not have all the information, which actively contributes to his worstcharactertraits.
Season 4 has Min-Gi and Ryan. Min-Gi’s self-confidence issues cause him to abandon his music dreams for university and a "safe" career in finance. Ryan tends to leap before he looks, which results in his career in music going nowhere. Both issues weigh heavily on their friendship.
Shendu is powerful and cunning, but his untrustworthiness and unwillingness to share power with others causes him to double-cross numerous characters, costing him many important victories and advantages later on.
Denying the Dark Hand the riches he promised them leads them to follow him back to his palace in order to take their price, and they also unknowingly transport Jade with them, allowing her to deny Shendu's certain victory over Jackie.
Trying to steal the Demon Archive from Jade while she was the Queen of the Shadowkhan by deceiving her resulted in her destroying it.
Also, Shendu betraying Daolon Wong after his resurrection makes the old wizard vengeful enough to the point that after being arrested, he tells the heroes Lo Pei's chi spell that is used to turn Shendu back into a statue.
Greed for the main trio of the Enforcers, which is why their first two attempts at turning good failed.
In the animated short, Life in a Tin, it's the main character's workaholic tendencies. When given the chance to take a day off and spend time with his child, he doesn't relent. It ends up killing him.
Most Akumas are created by exploiting someone's fatal flaws to the point where they create a conflict that Hawk Moth can exploit to brainwash them; in the first episode, for example, Stormy Weather comes into being because Aurore is jealous of Mirelle winning a contest instead of her.
Part of the reason that Chloé is such a brat is that the two people she's closest to - her father Andre and best friend Sabrina - have a lack of backbone as their fatal flaw. Neither of them is able to stand up to her, so she's used to considering them resources she can use to get what she wants.
Hawk Moth would never admit it, but the dude is having fun being a Card-Carrying Villain, resulting in him ignoring or rejecting ways to solve his core problem (his wife being in a coma due to using a broken Miraculous) in favor of the same old 'get Ladybug and Black Cat Miraculous and use them to make a wish' plan that keeps failing over and over.
All six of the main ponies suffer from some defining flaw that usually serves as a pivot for most of their personal dilemmas and even expand into full-blown disasters when exacerbated enough (almost all of them have suffered a Sanity Slippage at one point). While downplayed later in the series due to Character Development, they're still present:
The Arc Villain of the fifth season premier, Starlight Glimmer, has a big one: a lack of common sense. When faced with a problem, personal or otherwise, Starlight's first response is to use her absurd magical power to make it not a problem anymore, and she never thinks of the consequences until they've come back to bite her. Her childhood friend never contacts her again after getting his Cutie Mark? Cutie Marks are to blame for her unhappiness, so they must all be removed so nopony can ever leave her again. The Mane Six expose her as a brainwashing tyrant? Exploit Time Travel to ruin their friendship before it ever begins, Butterfly of Doom be damned. Even post-Heel–Face Turn Starlight has this problem, as her first instinct upon being told to socialize with other ponies involves things like magically compelling Big Macintosh to say everything that's on his mind and mind controlling the Mane Six sans Twilight.
Chrysalis's Fatal Flaw is her Narcissism and need for control. While a cunning strategist and Manipulative Bastard who's nearly conquered Equestria several times, she's shot herself in the hoof more than once by getting drunk on her apparent victory and congratulating herself before she's actually won, and her need to control is what exposes her to Twilight in her first appearance. Her inability to accept she's wrong and change how she runs her hive ultimately costs her everything in her second appearance.
Luz Noceda's major fatal flaw is her is her inability to think in the long term. On Palisman Adoption Day, abandoned palismen choose which students they go to based on what they want to do for the future; Luz does not get one because she doesn't know what to do for her future. And that's not even getting into all the times that she gets herself into trouble without putting any thought into how she's going to get out of it.
Prior to her Character Development, Amity Blight's major is flaw was Pride. As an Academic Alpha Bitch at the top of her class, Amity is destined to be one of the greatest witches of her generation due to her intense pressure to succeed. She has few friends, is ruthless, and is enraged when others threaten her position. She also holds contempt for those beneath her.
Sean's fatal flaw is that he fears cramped spaces, heights, and gets space-sick easily, but he must overcome these fears in time so he can achieve his dream of being an astronaut when gets older. He was also somewhat of a neurotic, overconfident perfectionist in the early episodes, but he gets better later on.
Jet's fatal flaw is his impulsivity. He tends to act before thinking, and this has caused trouble for him and his friends a few times throughout the show. He is also terrible at keeping the secret that he is an alien.
Rick's destructive tendencies (and his unwillingness to change) tend to put the lives of his family in danger and strain his relationships with them. Even Morty has his limits with Rick.
Tying into the above is that Rick is very prone to Didn't Think This Through often causing problems by using his science for quick fixes and never giving forethought to trouble down the line, forcing him to solve things as they happen.
His apathy. Rick's continual assertions that life is meaningless and that the existence of a multiverse means that all versions of everybody are ultimately expendable in his eyes has gotten turned around on him more than once. He was forced into complying with an ultimatum to either change his behavior or take off for a new universe because he showed this mindset, something which galled the usually arrogant Rick. He's also reluctant and possibly terrified at the notion of emotionally connecting with people, which leads Rick to self-sabotage nearly any relationship he has with others. The issues with Space Beth came about because Rick couldn't bring himself to make the choice Beth asked of him and instead tried to Take a Third Option which ultimately didn't resolve anything in long run.
Belligerence. Rick hates bending on anything to anyone else and has a habit of escalating problems and starting completely unnecessary fights with people, even when he has nothing to gain out of them, simply for the sake of his pride and Moral Myopia. Morty calls Rick out on this in the Season 5 premiere, pointing out that everything turns into a fight with Rick. He's proven right when Rick's shoots himself in the foot by having Summer show up and reveal his plan to screw over the enemy of the episode immediately after they offered a peaceful resolution.
His inability to stay committed to anything. Rick is notorious for only pursuing things because he finds them entertaining and tries to cut and run when it becomes more convenient to run away from problems instead of trying to actually solve them. This wreaks havoc on his personal relationships because he would rather take off and find some ultimately meaningless distraction instead of putting in the effort to better himself so he can keep the people he cares about in life.
Lust. His moralistic nature comes back to bite as well, but time and time again many of Morty’s darker moments or more idiotic stunts were motivated in some way by either Jessica or some random girl that catches his interest.
Rick: Pretty weird you were willing to sellout my existence for some trim, Morty!
His self-loathing is a variation of sorts, since while it leads him to make some poor decisions individually and often plays into his subservience to Rick, it's even more fatal among the numerous Mortys of the Citadel, particularly more immoral ones such as Cop Morty and Evil Morty who harm and even kill other Mortys out of hatred for what they represent of themselves.
Jerry Smith is insanely insecure. He is desperate for approval and affection, has no spine and at times he rivals Rick in the selfishness department. It's not always played for laughs and it causes problems for other people, including his family.
Beth Smith insecurity of feeling abandoned. She is willing to let her son go on dangerous adventures and go through a divorce with Jerry, hurting the rest of her family, so Rick wouldn't leave her. She overcomes this at the end of season three.
The Fatal Flaw of the Daughters of Aku is their Lack of Empathy. They were taught from an early age that needing help is a weakness and deserving of punishment, though this also means that they won't protect each other when they're on the defensive.
Jack's patience is legendary, but more often than not he allows his frustration to boil over with disastrous results. Specific incidents include getting so infuriated at a constant stream of bounty hunters that Aku was able to create an Evil Knockoff of him to fight, and lashing out in a blind rage after Aku destroyed the last known time portal in existence and then mutated the sheep that had helped him find the portal. That last one cost him his sword and sent him into a 50-year Heroic BSoD.
Evil Cannot Comprehend Good. Given that Aku is the Anthropomorphic Personification of evil, it's only natural that he suffers from this. Many of his schemes fail because he has no understanding of the concept of good. This trope is why him sending Jack to the future backfired. He'd expected a world ruled by him would allow him to crush Jack effortlessly when he arrived. He never took into account that a hero arriving and successfully resisting him would trigger Hope Springs Eternal and start giving the oppressed masses someone to rally behind. And in the series finale, his execution of Jack fails because he couldn't comprehend that rather than being crushed by this, the ones Jack inspired would come to his aid en masse. Later on in the same episode, he finally meets his end because he never believed his daughter Ashi could free herself from his control, letting her use his powers he awakened in her to take Jack back to the past and kill him.
Additionally, other things that are lost on him are "respect" and "teamwork", as he has Chronic Backstabbing Disorder to the highest degree and has actually screwed himself over time and again because he cannot help but betray his allies in some form or another, even when he's trying really hard not to.
Catra's biggest problem is an overwhelming sense of jealousy and utter inability to take responsibility for her actions. Her obsession with control, the past, and her inability to understand the responsibility she holds in her own life all stem from being jealous of someone else. She's her own worst enemy because she regularly makes stupid decisions to show up other people in her life, and when repeatedly given the opportunity to change her ways kept rejecting her chances because she'd rather lash out for perceived slights and convince herself that it's everyone else who's making mistakes. She eventually grows out of it when Double Trouble gives her a vicious"The Reason You Suck" Speech pointing out that everyone she genuinely cared for is gone and it's all her fault because she kept mistreating people in a desperate effort to prove herself and drove them all away.
In the first season, despite having a flashback of all their good times as childhood friends, Catra still turns her back on Adora, leaving her to die. Catra does this because if Adora is gone, it will mean Shadow Weaver will have to favor Catra instead.
Throughout the third season, Catra consistently makes things worse for herself out of jealousy. Catra lies that Entrapta is betraying the Horde, getting Entrapta sent to Beast Island. This actively hurts the Horde's plans, but Catra's jealousy over Entrapta getting close to Hordak means she doesn't care. Scorpia's suggestion that they live in peace in the wastes is ignored the second Catra believes Shadow Weaver joined up with Adora. Even in a reality where Adora offers Catra the chance to escape the Horde before becoming She-Ra, Catra still chooses to insist that Adora is abandoning her. Later in the same episode, Catra is willing to destroy the universe, herself included, just for the sake of beating Adora at something. Each time, Catra is offered opportunities to change but blames others for her own mistakes and lets her long-held grudges ruin her senses.
Maybe not as fatal as Catra's, but Entrapta's flaw is her overwhelming curiosity, combined with a complete disregard for consequences. As long as she can learn something, it really doesn't matter what happens. She does have her limits, refusing to perform an experiment that might destabilize the universe, but before that, she had destabilized the climate of an entire planet and was perfectly willing to open the door for an invading army, just because she might get the chance to learn from them.
Hordak's biggest fatal flaw is tunnel vision. Hordak is so fixated on projects of immediate importance to him that he overlooks dangerous developments right under his nose. Notably, he failed to grasp the full implications of She-Ra's re-emergence, the power contained in her sword, or her ability to unite the Princess Alliance.
Another one of his fatal flaws is arrogance. His arrogant attitude toward, and outright abuse of subordinates such as Catra and Shadow Weaver contributes to their disaffection, which has disastrous consequences for him. His arrogance toward the "inconsequential" Adora/She-Ra blinds him to the real threat she poses to the Horde.
Adora's biggest flaw is that she can be too controlling — when she wants to keep someone safe, she instinctively tries to fence them in so they can't get hurt. It's a holdover from her abusive childhood, when Shadow Weaver would torture Catra and tell Adora it was her fault for not keeping Catra under control. It does a real number on some of her most important relationships, especially since she doesn't really have the emotional intelligence to realize that she's doing it: Catra views Adora protecting her and telling her that she should change sides to get away from Shadow Weaver as attempts to put her back in Adora's shadow, while Glimmer in Season 4 takes Adora's actions as attempts to usurp her authority.
Glimmer's flaw is her sense of righteousness. In Season 1-3, she routinely goes against queen Angela's orders to do what she thinks is right, which sometimes works out and other times don't, but this flaw really starts becoming a problem in Season 4, when Glimmer becomes queen of Brightmoon. She still feels that she's always right, but now she has the authority to steamroll any objections. When Adora and Bow both object to her course of action because they know it won't work and only make things worse, Glimmer pulls rank on them and goes through with it anyway.
SpongeBob SquarePants: Squidward Tentacles is brought down by his hubris. His paintings and sculptures are pretentious and self-indulgent, and his clarinet playing is atrocious, yet he's so convinced he's an artistic virtuoso that he puts no effort in improving himself. Whenever someone (usually SpongeBob) proves to be much more talented than him, he refuses to accept it and berates him for not respecting True Art. A Flashback reveals that he thought working at the Krusty Krab would be a mere interim until his artist career took off, and smugly laughed at the possibility that it wouldn't. No prizes for guessing where that got him.
Steven Quartz Universe's main flaw is his self-sacrificing nature; he tries to take everyone's burdens on himself, even when it's obviously burning him out. This is made worse in Steven Universe: Future.
Connie Maheswaran keeps secrets and assumes that other people's reactions would be more negative than they are.
Lars has both severe social anxiety and self-esteem issues, leading to a defeatist mentality and a Jerkass Façade. His determination to seem as cool to others results in screwing up his relationships with Steven, Sadie, and the local teens. He gets better in Season 5 after a Disney Death and bonding with The Off-Colors.
Pearl has absolutely no self-esteem and depends on her relationships with others to feel good about herself. For most of her life, she was dependent on her Lady and Knight relationship with Rose, to the point where she couldn't accept her relationship with Greg or her decision to have Steven. She later almost completely ruins her relationship with Garnet by lying to her in order to keep Fusing, since as a fusion with Garnet she got to feel Garnet's self-confidence.
Amethyst also has no self-esteem, but in a different way. Her origin as a defective Gem from one of the Homeworld Kindergartens means that she thinks of herself as being a parasite on Earth, and she has little confidence in her own strength.
Garnet is an odd case since she's a Fusion and both Ruby and Sapphire have their own. Ruby's is her hot-headedness and single-minded focus on the present, to the point of not even trying to look for solutions to her problems. Sapphire's is her apathy and trust in her future vision; she is so invested in the future, she forgets that the problems she sees solved haven't been solved yet, and need her to act to fix them.
Rose Quartz had her Condescending Compassion and Innocent Insensitivity; while she really was an All-Loving Hero, she had no idea how deep that particular rabbit hole went. She didn't understand that humans could love on equal terms with Gems until Greg confronted her, and she was particularly bad at understanding how others felt, especially towards her. Some of this presumably came from being so isolated as Pink Diamond.
Blue Diamond and Yellow Diamond have opposite flaws; Yellow Diamond represses her emotions to the point that they cause her to act irrationally when they get too much, while Blue Diamond lets her emotions distract her from both her duties and from finding peace. White Diamond holds everyone to impossible standards of perfection, including herself.
Pink Diamond's flaw was her immaturity. She was the No Respect Gem among the Diamonds, and her frustration led her to throw tantrums to just get some attention from her sisters. She later grew out of it, but into others — see Rose's entry above.
Two fatal flaws are exposed in an episode of Teamo Supremo. Mr. Paulson admits to being too trusting. He tried to give his former lab assistant Crawford a second chance after he served his sentence for his villainous rampage as "the Gauntlet", only for Crawford to backstab Paulson and steal the Mega Gauntlets again. Paulson then reveals Crawford's flaw, his temper. He joins the team in confronting the Gauntlet and taunts him until, in a fit of rage, he hands the Mega Gauntlets over to Teamo Supremo so he can fight Paulson himself.
Robin tends to become so devoted to one goal, he neglects other aspects of his life until the issue is resolved. This characteristic has damaged, or even risked losing, many of his friendships and sometimes even proved his undoing.
Brother Blood is a genius and master manipulator, his flaw being perfection and pride. Once Cyborg proves resistant to his mind control, Blood becomes obsessed with finding out why, this one man he cannot control leading him to take foolish risks and bringing him to the brink of madness, and eventually, defeat.
Terra's is her inability to take responsibility for her actions, owing to being blamed for things that weren't her fault when her powers went out of control. This leads her to keeping secrets from the team, running away from her problems, and being an easy target for Slade to manipulate.
Mark Lily of Ugly Americans frequently gets into trouble with his lack of understanding of the various monsters of the world he lives in despite being a social worker, whether that be trying to treat them like humans or straight ignorance:
He temporarily killed Leonard by snapping his wand in half because he didn't know it was Leonard's life force.
He let a batboy out of its cage in an attempt to treat it with respect, unaware it was closer to a rabid animal than a person. It bites him on the penis, infecting him with its venom, and Grimes swoops in to kill it, aware of what was gonna happen.
Mark nearly killed a young manbird by trying a Die or Fly moment both because he thought it was ready and because he didn't want to try and teach him the manbird language, which consists of all swearing. The second part also means the manbird, Albert, will never properly communicate with his kind. Albert's singing even causes his father to disown him on his deathbed.
He nearly kills Randall, who was turned into a plant/zombie hybrid, by acquiescing to his demands for human brains, under the impression it was what Randall needed. Leonard points out it was closer to a baby demanding candy and Randall is dying of neglect.
His lack of knowledge of demons almost cost him his soul in one episode when he unwittingly agreed to a demonic ceremony with Callie. A recurrent problem in their relationship is also that it is clear Mark has no idea what he signed up for.
The Weekenders has Carver, whose desperation to be cool often leads him to make terrible decisions.
Winnie the Pooh: In "123's", Roo's major flaw is the inability to count over 6 and asks his friends for help.
Nerissa can gain control of the former Guardians by exploiting "the chink in the armor of their souls", leading her to tempt them with what they desire the most until they succumb to her influence.
Cassidy's is mercifulness. She unflinchingly refuses to be brought back to life when Nerissa tempts her with mundane things but is shaken after meeting her grief-stricken mother. Desperately wishing to reunite with her mom, Cassidy willingly submits herself to the villainess's control.
Halinor's is cowardice, as she attempts to steal W.I.T.C.H.'s powers for herself in a desperate attempt to protect Kandrakar from the Knights of Destruction. This single treasonous act is enough for Nerissa to corrupt her soul.
Kadma's is Pride. Nerissa purposefully loses a series of battles to boost Kadma's ego, after which the latter becomes convinced that she is destined to absorb the villainess's Heart of Meridian into the Heart of Zambala. However, since hearts cannot be forcefully taken, this action results in Nerissa claiming both jewels, while also enslaving her former friend in the process.
Yan Lin is a subversion. She is offered her youth, which would enable her to use her Guardian powers without draining her own life force; and the opportunity to protect Hay Lin, which she also turns down because she believes in her granddaughter's potential. Nerissa ultimately concludes that Yan Lin is incorruptible, and decides to create an Altermere to replace her, knowing that the clone wouldn't have the same strength of character when she threatened to erase her from existence.
Nerissa's is primarily Pride with serious hints of Greed: her entire Start of Darkness was because she couldn't stand Cassidy being given the Heart of Kandrakar instead and her ultimate downfall is because she can't resist going after the Heart of Earth by targetting Lillian's familiar Napoleon the cat during the Halloween Episode and her later attempt to screw over the rest of CHYKN and Elyon during the series finale backfires and traps her forever in a dream world.
While it is undeniably played for laughs most of the time, Omi, from Xiaolin Showdown has a massive superiority complex, constantly talks down to his friends as if they're beneath him, and it has gotten him in trouble more than a few times. Also demonstrated with Raimundo. Due to being singled out of a promotion and treated as inferior by Omi, again, Raimundo betrayed the team.
