->''"You are all bad boys and girls for kidnapping my dear Elise. You'll die for it!"''
-->-- '''[[VideoGame/FireEmblemFates Camilla]]''', ''VideoGame/FireEmblemWarriors''

You have a younger sibling. Either full-blooded, half-blooded, or just adoptive (or, in some odd cases, more than one of those at once). Especially a little sister. The kid is wronged somehow. What do you do?

Do you deal with the offender in a calm, civil manner?

Or failing that, perhaps you are a little upset, yet you keep control over your emotions, and keep yourself as restrained as you can?

Or do you go after the offender, the offender's friends, [[RevengeByProxy anyone connected to the offender]], as well as anyone who even looks like they could be an offender sometime in the indeterminate future and kill them all in as painful a manner as possible?

If you are the latter, then congratulations! You are officially a Knight Templar Big Brother (or Knight Templar Big Sister).

This trope is what happens when a character takes the BigBrotherInstinct to the extreme. They don't just protect the younger sibling, they absolutely destroy anyone who'd so much as even look at them wrong. Much like the KnightTemplar and KnightTemplarParent, the Knight Templar Big Brother often genuinely believes that what they are doing is right and fully beneficial to the younger sibling, [[WhatTheHellHero which often results in a clash of siblings later on within the show or work.]]

Contrast with SpartanSibling

See also: BigBrotherInstinct, KnightTemplar, KnightTemplarParent, MySisterIsOffLimits. If the characters aren't actual siblings, it probably is {{Yandere}}.


[[folder:Anime and Manga]]
* ''Manga/AttackOnTitan'':
** Mikasa Ackerman towards her adoptive brother Eren Yeager, since [[IOweYouMyLife he killed her parents' murderers, saved her from them, *and* let her into his family]]. She's violently over-protective, to the extent that she will ignore direct orders or the greater good (such as helping evacuate citizens) to protect him. On numerous occasions, she's threatened the lives of even her TrueCompanions, making it clear if forced to choose between Eren's well-being and their lives, she will kill them without hesitation.
** Levi was one to his [[DoomedByCanon ill-fated]] surrogate little sister, Isabel, in the SpinOff prequel about his past. When she came home beaten up and [[TraumaticHaircut missing a pigtail]], he went out. He comes home that evening, cleaning blood off a knife and won't answer when their companion Farlan asks if he killed those responsible. [[spoiler:When Isabel and Farlan both get eaten by an Aberrant, Levi [[UnstoppableRage loses it]] and utterly [[ThereIsNoKillLikeOverkill MASSACRES]] the Titan in question]].
* Lelouch Lamperouge from ''Anime/CodeGeass''.
** After his younger sister Nunally was wounded in a terrorist attack (that also killed their mother), he started a war and took over the world, all for her sake. [[spoiler: And when she found out, [[WhatTheHellHero she got]] ''[[WhatTheHellHero pissed]]''.]]
** In Season 1 Mao, a StalkerWithACrush to Lelouch's partner C.C, kidnapped poor Nunnally and strapped a bomb to her. Lelouch was ''already'' very pissed off at Mao, since he first [[spoiler: {{Mind Rape}}d his poor, sweet classmate -- and a total innocent bystander which he had no business to involve -- Shirley]] and then did the same to [[spoiler: his ForgottenChildhoodFriend Suzaku]]; needless to say, Mao did ''not'' meet a pleasing end.
--> '''Lelouch''': [[spoiler:[[CompellingVoice MAO]]! [[ShutUpHannibal NEVER SPEAK AGAIN]]!]]
* ''Manga/{{Bleach}}'' has a few examples:
** Ichigo adamantly believes the reason a big brother is born first is to protect all the little siblings that follow. He will force-feed this belief by the sword if he has to, to any big brother he catches not protecting their own siblings, as both Orihime and Rukia's respective big brothers discover. When he feels anyone he cares about is being threatened, he becomes single-minded about saving them, taking on both Soul Society and Hueco Mundo when Rukia and Orihime need rescuing from their respective hostage situations. When his entire family and social circle are brainwashed by a villain, he is left so isolated from the very people he is trying to save that he actually comes to accept that the only solution will be to kill the villain instead of simply defeating them. [[spoiler:When Yuzu dies in the fourth movie after being exposed for too long to Hell's miasma, Ichigo completely loses control, enters his super-Hollow form and destroys Hell's gate.]]
** Byakuya once made two separate vows: a promise to his dead parents that he would always uphold the law, and a promise to his dying wife to protect her sister, Rukia. When Rukia is sentenced to execution, those two vows conflict and Byakuya is forced to choose the vow that was made to his parents, which trumps a vow made to a wife. Ichigo helps him resolve the conflict, freeing Byakuya to do what he wanted from the beginning - protect Rukia. He does so with a dreadful, single-minded purpose; when Zommari decides to kill an unconscious Rukia, Byakuya intervenes. When Zommari is defeated, he rants about Shinigami arrogance in thinking they have the right to slay hollows. Byakuya corrects him, explaining that killing Zommari has nothing to do with being a Shinigami and that it's instead because Zommari dared to point a sword at Rukia.
** Hitsugaya and Hinamori have been raised together by an old woman they both refer to as their grandmother. He is incredibly protective of her despite being the younger of the two to the point where he attacked a perceived threat to her with such force two nearby vice-captains were caught up in the power he unleashed (one of which was actually her). [[spoiler:In the end, their relationship is exploited by Aizen, who tricks Hitsugaya into stabbing an illusion of Aizen - when the illusion disappears, it's revealed that Hitsugaya has stabbed Hinamori. As a result, Hitsugaya vows to become strong enough to protect Hinamori from everything.]]
** A deconstructed case with the movie character Kokuto within the franchise. His younger sister got killed and Kokuto killed her murderer, but Kokuto got punished later on and ended being in Hell in his after life. [[spoiler:He could not accept his punishment and tries everything to break out of Hell, even going so far to manipulate Shuren and his men to lure out Ichigo to Hell and use his Hollow powers to break his chains. This is where the {{Foil}} part kicks in. After Ichigo's sister is revived, Ichigo returns to Hell to save his friends from Kokuto's hands and not to seek revenge on him, while Kokuto's desire for freedom comes from his hatred for his punishment, as he thinks that he doesn't deserves that for revenging his sister. Hell sympathizes more with Ichigo and lend him its power to defeat Kokuto, who then gets punished ''even harder''.]]
* Henry Wong from ''Anime/DigimonTamers'' went from being the most rational and calm guy in the group to being temperamental, hasty and reckless when his sister ends up in the Digital World.
* Caren, the AloofAlly of ''Manga/MermaidMelodyPichiPichiPitch'', starts dangerously close to this, having been perfectly fine until her twin sister was kidnapped. However, while she blames and berates the good guys as well as the bad, she does do a lot of [[IWasJustPassingThrough reluctant rescues]] and admits that she was wrong instead of going off the deep end.
* Another Knight Templar ''Younger'' Brother is [[spoiler: Fire God Apollo]] from ''Manga/{{Cyborg 009}}'', towards his older sister [[spoiler: Hunt Goddess Artemis]]. When [[spoiler: the girl died [[TearJerker very tragically]], the already unstable Apollo went literally ''insane'' with grief and killed the culprit, then let himself die whispering his sister's name]].
* Ran Fujimiya in ''Anime/WeissKreuz'' is downright obsessively protective of his IllGirl little sister Aya. He became an assassin in large part to pay her medical bills (she's in a coma), and he is not in the least bit rational about threats to her safety.
* ''Manga/{{Naruto}}'':
** Kankuro becomes one of these as a part of his CharacterDevelopment, reacting violently to anyone who badmouths his little brother Gaara in front of him and going after Gaara alone after [[MadArtist Deidara]] and Sasori of Akatsuki kidnap him and Kankuro's team mates are nearly all killed in an explosion. Given that Gaara used to be an AxCrazy psychopath who regularly threatened to kill Kankuro, this is quite a drastic change. Sadly, it all goes horribly wrong when poor Kankuro gets his arse handed to him by Sasori, and Sakura barely manages to save him.
** Kinkaku seems to fit here as well. He and his brother, Ginkaku, are SiblingsInCrime who work well together. Ginkaku's most used word in his life being his brother's name. In their battle, Ginkaku is backed into a corner, and he calls for his brother's help, but him saying his brother's name gets him sealed, as he wasn't supposed to say his most-used word at the time. In response to this, Kinkaku flies into rage [[spoiler: and undergoes bijuu transformation.]] Kakuzu, nearby states something must have happened to Ginkaku because it's been ages since he saw Kinkaku in such a state. Darui apologizes to Kinkaku, but he just states it's too late and attacks anyhow, and rips through the division like crazy. Special preparations had to be made in bringing down Kinkaku, with the Raikage stating he was unstoppable otherwise. Prior to Ginkaku's sealing, Kinkaku was rather stoic, [[http://ic.pics.livejournal.com/silverfang2/29185537/579986/579986_1000.png averted in the anime]].
** There's also the Raikage. When he is told his brother Killer Bee was killed by Akatsuki his response was to call an international meeting to stop Akatsuki. When he found Sasuke he became so hellbent on revenge that he didn't even care if he [[spoiler:lost his arm]] to kill him. And [[spoiler:his leg]], too, if Gaara hadn't stopped him. It's also possible that, despite all that, if Gaara hadn't stopped him, Sasuke would have ''died.''
** [[spoiler:Itachi Uchiha]] towards [[spoiler:Sasuke ''and'' the Leaf Village.]] The whole Uchiha Massacre episode was set up to [[spoiler:protect Konoha from the coup d'etat his own father was planning, and though he was able to kill both of his parents, his best friend, ''and'' his girlfriend, he couldn't bring himself to kill Sasuke]]. He even went so far as to threaten to ''leak the village's information to every rival village'' if [[spoiler:Sasuke was ever hurt due to something the leaders of Konoha had done or ordered]]. Let's not even discuss the deal with their fight to the death or the fact that [[spoiler:Itachi let Naruto get away from him after said IdiotHero promised to straighten the then-rogue Sasuke out]]. And after what happened to Madara when Sasuke [[spoiler:saw his Sharingan]], it's rather [[AndIMustScream frightening]] to imagine the exact consequences of someone doing anything to [[spoiler:permanently injure Sasuke.]]
** Neji Hyuga becomes this for his younger cousin Hinata in ''Manga/RockLeesSpringtimeOfYouth'', where he beats up and kicks everyone who wrongs Hinata. He mostly does it to Naruto, because Naruto obliviously says inappropriate things to Hinata, which leads to Neji beating the crap out of Naruto. There is also this instance where Hinata timidly approaches Naruto, Neji, and Lee. Neji tells Naruto and Lee to be patient with her and wait for her to speak. More than twenty minutes pass and then Hinata finally gathers the courage to say something about the weather, which makes Naruto and Lee burst out ''That was it?!'', making Hinata feel bad and depressed, [[CrowningMomentOfFunny which makes Neji kick Naruto and Lee into space]].
* ''Manga/OnePiece'':
** It's the younger brother, Monkey D. Luffy, that deploys this behavior. He goes on a ''rampage'' once he hears that his older brother, Portgas D. Ace, has been taken captive by the [[TheGovernment World Government]] and is on death row. He not only breaks into the heavily-guarded Impel Down and nearly gets himself killed by trying to go against the BigBad Magellan, but also decides to go further to the Marine HQ when he [[YourPrincessIsInAnotherCastle fails to make it in time to prevent his brother from being transferred to his execution site]]. He also gets furious when he comes face-to-face with the man responsible for his brother's capture. When Luffy is taunted that part of the reason that Ace went up against the man is that he [[AndYourLittleDogToo threatened to kill Luffy and turn him in for his bounty]], Luffy [[UnstoppableRage loses control, attempts to flatten him]], and has to be reminded that saving his brother is more important than avenging his defeat.
** Played straight with the older brother Ace. When he found out that Luffy was being targeted, [[BigBrotherInstinct he wasn't]] [[http://read.mangashare.com/One-Piece/chapter-440/page014.html pleased at all]].
** Rounding out the brothers is [[spoiler:the not-quite-dead Sabo. There isn't ''anything'' Sabo wouldn't do for Luffy, his precious baby brother and, with Ace's death, the only family he has left in the world. In fact, the only reason Sabo hadn't joined the war to save Ace is because of amnesia -- which was only cleared up when he read an article ''detailing Ace's death''. Hence, Sabo is willing to cut a bloody swathe throughout the entire damn world if it meant protecting his only remaining brother]].
%%** Let's just say threatening Luffy's a ''very, very, very bad idea.'' Basically? Don't mess with Luffy, if you value your life.
* MadScientist Komui Lee of ''Manga/DGrayMan'' is very protective of his younger sister, ActionGirl Lenalee. So much so that Link, wanting to go into a room which Allen had locked him out of, threatened him with, "you leave me no choice. I am forced to tell Supervisor Komui that you are in a sealed room with Lenalee Lee," to which Allen quickly apologized and let him in. There is also an anime-only {{filler}} episode where Komui mistakenly thinks that Lenalee is going on a date with one of the Order's scientists and has to be convinced to simply stalk them all over town instead of outright killing the guy. He then repeatedly tries to attack and is comically restrained, until eventually he manages to summon a huge robot to aid him. An excellent summation:
-->'''Reever:''' "Section Chief Peck, I would advise you [[MaleGaze not to look at Lenalee that way]]."
-->'''Peck:''' "Why? Does she have a lover?"
-->'''Reever:''' "She has a ''brother''."
* Ryo Mashiba from ''Manga/HajimeNoIppo'' was orphaned when he was in high school, so he had to [[PromotionToParent raise his younger sister Kumi]] on his own. Being a borderline SociopathicHero, he ends up as this towards her, and it's both played for drama ''and'' for hilarity.
* Subverted with Seimei Aoyagi from ''Manga/{{Loveless}}''. To him, it doesn't really matter HOW you treat his younger brother Ritsuka. Seimei believes that [[{{Yandere}} Ritsuka belongs to him and will get rid of anyone in his way]].
* This trope is revealed to be [[spoiler: Folken Lacour de Fanel]]'s main motivation in ''Anime/TheVisionOfEscaflowne''. [[spoiler: Having failed to pass the Dragon rite (and having been mutilated in the process), Folken joined Dornkirk in hopes that he could create a world where his younger brother Van won't have to fight as king.]]
* Kayo's brother in the ''Manga/VampirePrincessMiyu'' TV series has a BigBrotherInstinct at first and then becomes this, trying to kill Miyu for getting close to his baby sister.
* In the manga of ''Manga/DeathNote'' Light Yagami claims in an early MotiveRant that part of the reason he's killing criminals ''en masse'' is to make the world a safer place for his little sister Sayu.
** It might even be somewhat true. [[spoiler: Sayu is, after all, the only person he refused to kill when it would be to his advantage to kill her. Then again, it could be that he just realized Mello would keep kidnapping people until he finally did something about it other than kill their prisoners.]]
* In ''Manga/HellTeacherNube'', the demon Bakki can bounce between LaughablyEvil and evil... but if you hurt his little sister Minki, you. are. DEAD.
* Deconstructed in ''Anime/OvermanKingGainer'': [[BigBad Asuham Boone]] will react violently (and {{disproportionate|Retribution}}ly) towards any slight to his younger sister Karin, even minor or ''imagined'' ones. The whole reason why he wants to capture [[TheLancer Gain]] and thwart the Exodus is that he had convinced himself that Gain had seduced and abandoned her, [[spoiler:while the truth is that Gain and Karin had a one-night stand and Asuham overreacted]]. It gets so bad that [[spoiler:during the last episodes, Asuham goes insane with rage and decides to destroy both Gain and the Exodists by awakening the Overdevil, a world-ending EldritchAbomination]]. He gets better, though... Perhaps [[KarmaHoudini too much]].
* ''LightNovel/ACertainMagicalIndex'':
** When Last Order is kidnapped, [[spoiler: Accelerator]] reverts back into the person he used to be, except in an effort to save her. Slaughter ensues. The lesson in all this? Only those who don't value their lives shall mess with Last Order
** Mikoto also has shades of this herself when she discovers what's happening to her clones, whom she considers her younger sisters, and what she's willing to go through to stop the Level 6 Project.
* ''Manga/DetectiveSchoolQ'': [[spoiler: Kunihiko and Akihiko Ichinose]] become this, trying to protect [[spoiler: their sister Kaoru]] from a SmugSnake aunt who wants to become her tutor and steal the fortune she inherited from their MissingMom alongside a PhonyPsychic accomplice. [[spoiler: They kill the psychic first, and then they murder the aunt when she finds out and tries blackmailing them. Only the psychic was their mom under a disguise, having faked her death to save her business and watch over her kids. Whoops.]]
* Both inverted and played straight in ''Manga/FullmetalAlchemist.''
** Edward is multiple times in the series confronted with the question of how far he's willing to go to save Alphonse, but sanity and morality usually win out. However, in an early episode of [[Anime/FullmetalAlchemist the 2003 anime adaptation]], Alphonse comments that if something were to happen to Ed, Al might well go on a killer rampage just like [[spoiler:Scar]] did.
** Scar counted as one himself. The realization of his brother's death sent him into an uncontrollable rage, during which time he [[spoiler:killed the Rockbells]]. He later moves on to hunting down and murdering State Alchemists to avenge him.
* Phoenix Ikki of ''Manga/SaintSeiya'' embodies this trope when his little brother Andromeda Shun is involved, to the point that putting Shun in life-threatening danger became the default way to work Ikki into any given storyline.
* In ''Manga/ChronoCrusade'':
** When Rosette Christopher's little brother is kidnapped by the BigBad, she makes a DealWithTheDevil and spends four years training as a ChurchMilitant. The moment she discovers the location of her brother, she travels from New York to San Francisco, guns blazing, killing any demon that attempts to get in her way, all while being the only BadassNormal in the manga ([[spoiler:the anime eventually gave her holy powers]]). In the manga, it all leads to a battle between her and [[spoiler:Joshua Christopher himself]] who is strong enough to tear apart a massive army of demons with his bare hands. ''And she kicks his ass.''
** There's also Fiore, who considers herself as something of a big sister to Joshua. She seems gentle and demure at first, but when the time comes she doesn't hesitate to [[spoiler:die in an attempt to protect Joshua, even going directly against her master's orders in the manga]].
* ''LightNovel/{{Durarara}}'''s Shizuo Heiwajima tends to act like this in regards to his little brother, Kasuka. While he has reason to be concerned for his brother's safety and privacy (Kasuka's a popular actor, and has been stalked by both rabid fans and the paparazzi in the past), Shizuo takes it a bit too far by immediately becoming suspicious of ''any'' mention of his brother by strangers, innocent or otherwise. Said suspicion [[HairTriggerTemper usually escalates into]] [[SuperStrength tree-throwing]].
* Touya from ''Manga/CardcaptorSakura'' has shades of this because he promised his mother on her deathbed that he'd protect Sakura. For one, he jumped over a fence and tried to beat up a 10 year old boy for bullying Sakura.
* Inverted in ''Manga/RurouniKenshin'' in that Enishi is a Knight Templar ''Little'' Brother. So concerned about his older sister's well-being and so seething with pure hatred toward his brother-in-law for [[spoiler: killing Tomoe's fiance]] that Enishi collaborated with a league of Shogun assassins alongside his sister in order to kill Kenshin - and this was while he was ''nine''. [[spoiler: After witnessing Kenshin's (accidental) killing of Tomoe, Enishi's hair went white from shock and stress and he dedicated his life to taking {{revenge}} on the man who killed his sister (going as far as selling weapons on the black market to fund his plans) as he felt he had nothing left.]]
* Lets not forget Urd from ''Manga/AhMyGoddess!'' Urd makes it clear that she will do anything and use any power she has to in order to protect her sisters, Belldandy and Skuld. Urd has to continually "punish" Aoshima after his latest rape attempt against Belldandy or Skuld (he tried to force himself on her when Skuld grew up after Yggdrasil crashed). Urd stood up to her own mother Hild, the Daimakaicho, telling her to stop tormenting "her little sister" Skuld after Skuld incurred her wrath. Also, Urd actually passed the test to become a First-Class Goddess (the highest level that every goddess tries to attain) but declines because First-Class Goddesses have to use their powers to protect everyone; Urd only wants to use her powers to protect her sisters. Since Belldandy goes absolutely postal if anyone even blinks wrong at Keiichi, it is easy to overlook that Urd is a Templar Knight Big Sister as well.
* Akira's older brothers in ''Manga/AiOreLoveMe'' are quite protective of him.
* More than one SympatheticMurderer in ''Manga/DetectiveConan'' is a brother or a sister seeking revenge for the death or ruin of their younger or older sibling. Some examples are [[spoiler: Toshiya Tadakoro (kills his boss for causing the death of his IllGirl sister while MovingTheGoalposts)]], [[spoiler: Akiko Sayama (kills a corrupt PC programmer for causing her older brother's ruin and suicide)]], [[spoiler: Chieri Aki aka Eri Akechi (kills two {{Alpha Bitch}}es for framing her long-lost younger sister for drug trade and making her commit suicide)]], [[spoiler: Masao Kouda (doesn't kill anyone but becomes a bank robber to hide his loot in the backyard of the man who killed his younger sister and force them dig in to find the girl's corpse)]], [[spoiler: Midori Nozaki (brews a mix of FatalMethodActing and ThanatosGambit to both commit suicide and [[TakingYouWithMe take the woman]] who made her sister kill herself down with her)]] and others.
* [[spoiler: Kanba Takakura]] from ''Anime/MawaruPenguindrum'', as of episode 21. [[spoiler: It ends with his RedemptionEqualsDeath.]]
* Romano from ''Manga/AxisPowersHetalia'' ''tries'', bless him. Luckily for Germany, he can't throw a grenade properly and can't come up with anything worse than [[PlayedForLaughs holding up a stupid mustache so that it looks like Germany's wearing it then breaking down in tears when Germany points out that from his angle, it looks like Romano's the one wearing it]].
** Depending on your interpretation of their relationship, Spain is either this, PapaWolf or [[HoYay something]] [[ShipTease else]] entirely to Romano.
*** Done ''literally'' and averted with Germany and Prussia. Prussia used to be the physical personification of The Knight Templars, and is Germany's older brother, but doesn't actually ''act'' like a Knight Templar brother.
* In ''Manga/HunterXHunter'', Illumi Zoldyck's feelings for his younger brother Killua are...intense. He is extremely overprotective and possessive of him. Being creepy even by the standards of a family of assassins, his protectiveness manifests in twisted ways. [[spoiler:Such as shoving a needle into Killua's brain to make him into a coward who will flee from any confrontation against a powerful opponent.]] Threatening Killua is also Illumi's BerserkButton. During an otherwise civil conversation, the very moment Hisoka implies he wants to kill Killua, Illumi puts on a NightmareFace and radiates a killing aura so intense that Killua can feel it from miles away. He immediately calms down when he realizes Hisoka was trolling him. Note that Illumi only feels this way towards Killua. He seems indifferent towards Milluki and Kalluto [[spoiler:and he wants to kill/enslave Alluka.]]
* Kagetsu of ''Anime/ShamanicPrincess'' adores his little sister Sara. So much so, that when the PowersThatBe give her as an offering to a powerful sentient magical artifact, he steals the artifact at the risk of causing the collapse of his world to save her.
* Vincent Nightray from ''Manga/PandoraHearts'' is one year younger than his brother Gilbert, but his [[{{Yandere}} obsessive]] [[IncestSubtext love]] for him definitely qualifies for the trope. When they were children, [[spoiler: Vincent used his [[ApocalypseMaiden Apocalypse Lad]] powers to destroy ''an entire city'' in order to save his brother.]] In present time, Vincent's stated goal is to [[spoiler: [[SuicideForOthersHappiness erase his own existence so that Gilbert will be happier.]]]]
** Another possibility is Xerxes Break from ''Manga/Pandora Hearts'', towards Sharon Rainsworth. While it's not specified if they had romantic feelings for each other or simply a strong familial connection, on the event of the latter, Break certainly qualifies. [[spoiler: When Sharon is struck in the face by a Baskerville while trying to protect him, Break, despite being damn near ''collapsing'' from the strain on his body, absolutely refuses to stop massacring the Baskervilles until he avenges her resulting injury.]]
* Shuzen Akua/Akua Shuzen from ''Manga/Rosario Vampire''. So much as threaten her little sisters, and ''you die'', regardless of who you are. Even her [[spoiler: grandfather, the super-powerful and ancient vampire Alucard.]]
* During the years of ''Anime/PrettyCure'', many of the Cures who have siblings got angry when a villain dared to attack those said siblings, but the only one who got ''really'' mad was none other than [[Anime/FutariWaPrettyCure Cure Black]], who actually ''killed'' a villain (Gekidrago) for revenge of hurting her AnnoyingYoungerSibling.
* Shinnosuke from ''LightNovel/ApocalypseAlice'', who tries very hard to be TheUnfettered in wanting to save his little sister. To achieve that goal, he's sworn off anything unnecessarily detrimental to him, such as sticking his neck out for others as he can't afford to die before rescuing his sister. That said, keyword is ''tries''.
* Shouri Shibuya, the protagonist's older brother, from ''LightNovel/KyoKaraMaoh''. He always felt responsible for protecting Yuuri, so after learning his little brother's eventual fate to become the Maou of another world when both of them were children, Shouri decided to get strong enough to continue protecting him even as Maou. Unfortunately, he wasn't there yet by the time Yuuri actually went to the other world, and on top of that his little brother found protectors ''in'' that world who were more capable than Shouri could hope to compete with. Neither of these things sat well with him, and his struggle to deal with this and learn to let Yuuri go be king is a major part of his character arc.
* Yami Yugi from ''Anime/YuGiOh'' is this towards Yugi (and later, Yugi's friends as well) in the earlier issues of the manga and season 0 of the anime, viciously destroying anyone (both teenage and adult) who bullies or otherwise hurts them by playing sadistic games with ''Franchise/{{Saw}}''-like stakes or by invoking magical penalty games that [[MindRape drive them insane.]] Sometimes the bullies' actions are severe enough to warrant it, but most are DisproportionateRetribution. He also shows this to a lesser degree in the Duel Monsters anime, particularly in season 1 [[MoralityPet (before Yugi's influence mellows him out)]], and in season 4 [[MoralityChain (when Yugi's soul is stolen.)]]
* Tatsuya Shiba from ''LightNovel/TheIrregularAtMagicHighSchool'' has this for his sister Miyuki. Even when [[LadyOfWar she's quite capable of defending herself]], it's best not to threaten her, or Tatsuya will make the culprits '''p a y'''.

[[folder:Comic Books]]
* [[ComicBook/StrangersInParadise Katina Choovanski]] is quite capable of taking care of herself, but her crimelord sister still keeps interfering in her life - sometimes by [[VillainyDiscretionShot killing people horribly]] because they tried to hurt Katchoo, sometimes by trying to ensure that she ends up with the "right" love interest. Our heroine does not appreciate this.
* [[Comicbook/TeenageMutantNinjaTurtlesMirage Raphael]], while not being the most [[SociopathicHero even-tempered]] character, is psychotically protective of little brother Michelangelo - to the point where he states that the 'thought of Mikey being hurt makes him experience violent rage' (see [[Wiki/{{Wikipedia}} The Other Wiki]]). And considering how violent Raphael is usually...
* Comicbook/SheHulk and the Comicbook/IncredibleHulk are cousins, but they have a Brother/Sister relationship. She-Hulk can take care of herself most of the time, but pity the poor fool who harms She-Hulk within proximity of The Hulk. She-Hulk herself can be extremely overprotective of The Hulk as well. Comicbook/IronMan got his ass handed to him by Ms. Hulk when she found out Stark [[PlanetHulk exiled Hulk into space]].
* How about that time ComicBook/{{Nightwing}} freakin' ''killed'' ComicBook/TheJoker with his ''bare hands'' when he thought he killed [[Comicbook/RobinSeries Robin]]? Of course, ol' {{Franchise/Bat|man}}s quickly revived him afterwards, but even still.
* ComicBook/{{Quicksilver}} for the ComicBook/ScarletWitch, except that he is her twin, not big brother. But [[RealityWarper recent portraying of Wanda's power]] suggest that if you attack Wanda, you are lucky if Quicksilver kicks your ass before ''she'' has to use her power.
* ''Comicbook/TheMightyThor'': Thor's brother Loki is a manipulative, deceitful god of lies and mischief, and he often does bad things and sometimes gets punished for them… but if you dare hurt him unjustly Thor will smite you from the face of the Earth.
* In ''Comicbook/UncannyXMen'', ComicBook/{{Colossus}} is this toward his sister ComicBook/{{Magik}}, to the point where he allowed himself to be possessed by the demon Cytorrak and became the new Juggernaut to protect her, losing his humanity and the love of Kitty Pryde in the bargain. Subverted in ''ComicBook/AvengersVsXMen'' when Illyana reveals she had manipulated him into becoming the new Juggernaut to make him see that she wasn't his sweet little sister anymore but a monster he shouldn't care for. Right off the bat Colossus vows that he would kill Illyana if they ever met again, but later they make up.

[[folder:Fan Works]]
* The Kage Tenshi's [[FanficRecs/MartinMystery The Red Monarch's]] Sousuke Miyabe is one for his little sibling [[OriginalCharacter Tatsuki]]. To put things into perspective, 10 years ago, he [[spoiler: kills several Center agents, nearly kills M.O.M and [[OriginalCharacter Colin Price]] and even kills his own parents when they try to protect Colin.]] Tatsuki saw ALL OF THIS, which comes back in literal nightmares. To get the full story, if you read the spoilers, read [[http://www.fanfiction.net/s/3645440/1/The_Red_Monarch/ The Red Monarch]] until you reach the most recent chapter, as it is still ongoing. The link directly to the story is provided for convenience.
* In Murderer's Row, a [[AlternateUniverse Prison AU]] of ''Machinima/RedVsBlue'', Grif and Simmons were thrown in prison for murdering a man who hospitalized Sister.
* In ''Fanfic/MagicaMadokaVeneficusPuella'', Sayaka adopts an orphan. Someone kidnaps her. [[CaptainObvious Do the math.]]
* In ''Fanfic/KitsuneNoKenFistOfTheFox'', Neji is a Knight Templar Older Cousin for Hinata, going to varying lengths to keep Naruto away from her, up to and including attempting to manipulate events so Naruto will get kicked out of Konoha High School. Hiashi approves, especially after they find out Naruto was one of the legendary Nine Terrors, but Hinata herself is not pleased.
* ''Fanfic/ThisBites'':
** Ace, as per canon. Cross has a distinctly ThisIsGonnaSuck reaction when he's about to reveal to Ace and Luffy that [[spoiler: their other brother Sabo is still alive]], because he knows that not only will Ace not believe him, but will see it as nothing more than an extremely cruel manipulation. Cross promptly gets subjected to near-strangulation and the full force of Ace's Conqueror's Haki. This is the ''best-case scenario'' Cross imagined - Luffy later confirms that if Cross had gone about it with any less delicacy he would likely be dead.
** When [[spoiler: the SBS accidentally broadcasts ''everything'' that happens on [[Film/BaronOmatsuriAndTheSecretIsland Omatsuri Island]]]], the people who are traveling with Ace have to constantly keep up their own Haki to avoid being incinerated just from standing near him. [[NightmareFuel This is an entirely reasonable reaction]] [[AdultFear for Ace to have, of course.]]
* In the ''Manga/PandoraHearts'' post-series fanfic ''Fanfic/BeyondTheWindingRoad'', Anderson is this to Oz, doubting that Oz can take care of himself due to his past mental health issues. He goes after Gilbert, whom he sees as a stalker, with all the viciousness of a bull shark. It's sort of justifiable, though, as Oz is implied to have had problems with stalkers in the past and had too many psychological issues then to deal with it himself. Anderson even accuses Gilbert of going along with his brother's "delusions" just so he can find a psychological trigger.
* In the ''{{Anime/Bleach}}'' PeggySue fic ''Fanfic/HogyokuExMachina'', when Ichigo learns of Toshiro Hitsugaya's interaction with his sister Karin (soccer game, anime filler), and is led to believe that she had developed a crush on her, the first words out of his mouth are "He dies." Toshiro, who is eavesdropping along with many others, is understandably disturbed. Later, after Ichigo reenters the Final Getsuga Tensho form…
-->'''Ichigo''': You saw everything? All of you?
-->''(Yamamoto nods)''
-->'''Ichigo''': Good. Hitsugaya-taicho.
-->''([[FlashStep Flash Steps]] next to Toshiro and puts his hand on his shoulder, one finger dangerously close to his neck, and the cloth Ichigo is touching begins to burn away from contact with Ichigo's PhysicalGod state)''
-->'''Ichigo''': Stay out of the living world.
** What makes this particularly effective? Ichigo always addressed the Squad 10 captain as Toshiro, regardless of how many times the latter demanded to be called Hitsugaya-taicho instead. The circumstances surrounding the above interaction make it so that, when he finally uses the preferred title, the captain immediately begins praying that Ichigo would call him Toshiro again.
* ''FanFic/{{Rules}}'': Deconstructed. Light tries to rationalize his use of the Death Note as a way to protect Sayu. [[spoiler:A bad car accident later, Light almost kills the innocent drivers of the other car with the Death Note. After Elijah/L manages to make him see sense, Light comes to the bitter realization that even if he manages to make sure ''criminals'' will never harm Sayu, he can do nothing to stop random accidents or diseases from doing the same]].
* ''Fanfic/PokemonResetBloodlines'': Belladonna is murderously protective of her girlfriends, so it is no surprise she is this for her [[spoiler: potential half-brother Ash. When she learns that he has suffered loss at the hands of a jerk, she vows to make that person pay]].
* Jon is this to Abby in ''Fanfic/LegacySeries.'' If you so much as lay a finger on her without her consent, he will get very, very protective. And since he's the new incarnation of [[BadassNormal the Arrow]], you ''really'' don't want him mad at you.

* ''Film/TheBlindSide'': Michael is usually a GentleGiant, but [[spoiler: a drug dealer hits Michael's BerserkButton by [[WhereDaWhiteWomenAt making sexual comments]] about Collins, and Michael flies into an UnstoppableRage.]]
* Do not hurt Molly in ''Film/SleepawayCampIIUnhappyCampers'', emotionally or physically. Angela will kill you for it. Just ask [[spoiler:Ally, who was ''drowned in an outhouse'']] for committing that crime!
* When the protagonist of ''Film/SickGirl'' finds out her little brother's being bullied, she hunts the three bullies down, kills one of them, and forces the lead bully to drown the other, then ties him up in her barn and spends several days torturing him to death.
* ''Film/DeadMansShoes''. Somewhat after the fact, older brother Richard returns from the army after discovering his brother has been bullied and goes about giving the bullies a taste of their own medicine with interest.
* Haru from ''Film/BeverlyHillsNinja'': "I may not be the Great White Ninja, I may not be one with the universe but I know this...NO ONE MESSES WITH MY BROTHER!"
* The titular character of ''Film/GingerSnaps'' starts out as a Knight Templar Big Sister and gets steadily worse over the course of the movie, as her transformation into a werewolf makes her more and more aggressive. For example, she kills the janitor because she thought she saw him look down Brigitte's top earlier in the movie.
* In the 1938 Yiddish film ''Mamele,'' Khavkhe (Molly Picon) takes care of her whole family. A gangster, Max Katz, recruits her brother into a burglary gang, and courts her sister (with the intention of turning her into a prostitute). Khavkhe manages to pickpocket Katz's gun, and makes him write a letter breaking up with the sister. ("You may be a Katz (cat), but you'll leave here as a kitten.")
* ''Film/FourBrothers'': Bobby Mercer is already pretty [[BloodKnight violent]] [[HairTriggerTemper and short-tempered]] to begin with, but [[BerserkButton hurt his younger brothers]] and he ''[[IllKillYou will]]'' put you in either the hospital or a body bag. He proves this multiple times throughout the movie, especially when he goes on a [[RoaringRampageofRevenge murderous rampage]] against Detroit crimelord Victor Sweet and his cronies after [[spoiler: the murder of youngest brother, Jack]].
* Tony Montana from ''Film/{{Scarface 1983}}'' is just a ''tiny'' bit overprotective of his little sister Gina, even going as far as [[spoiler:murdering Manny Ribera, his best buddy, [[MySisterIsOffLimits for sleeping with her behind his back]]. However, unbeknownst to him, said friend had married Gina the day before]]. Worth noting that more than one critic has observed an [[IncestSubtext incestuous undertone]] to some of Tony's actions [[spoiler:of which Gina also accuses him when she tries to kill him in revenge.]]
* ''Film/AlphaDog''. When Jake Mazursky learns that Johnny Truelove has kidnapped his little brother Zack to get back at Jake, he promises his estranged stepmom that he will do anything to get Zack back. Jake immediately goes on a rampage, crashes a local house party held by some of Truelove's friends by beating up half the people in the room and when Truelove calls him up, Jake threatens Truelove with enacting brutal and painful vengeance unless he releases Zack. Subverted however, as it doesn't help Zack's return at all and prompts Truelove to relocate with his victim.
* ''Film/AmericanHistoryX'': Derek threatens to feed Cameron's heart to him if he continues trying to corrupt Danny like he did with him.

* ''Literature/CalLeandros'':
** Niko Leandros would burn the world to protect his brother. The only reason Cal ever gets near to any combat is because Nico is a firm believer that the only way to be ready for combat is to actually participate in it.
** Cal reciprocates the sentiment just as strongly. And considering he's slowly slipping into a [[SociopathicHero Sociopathic Type V]] AntiHero over the course of the series with Niko as his sole MoralityChain...the question isn't ''if'' he kills you, but how much he'll make it hurt before he does so.
* [[spoiler: James Vane]] from ''Literature/ThePictureOfDorianGray''. His little sister [[spoiler: Sybill]] killed herself when he was working abroad, so when he found out, he swore to kill the culprit, Dorian Gray. [[spoiler: He ''almost'' got his wish, but was accidentally shot to death.]]
* In ''Literature/HellsChildren'', by Andrew Boland, you never, ever mess with Acheri, or her de facto big Brother, Precision, will MindRape you.
* If you decide to [[spoiler: kill and eat]] [[Literature/TheSilenceOfTheLambs Hannibal Lecter]]'s baby sister, don't be surprised when her brother tracks you down and makes a shish-kebab of your cheeks. With mushrooms.
* Gretchen Richter in ''Literature/SixteenThirtyTwo'' is a gender-switched version of this, for her brother Hans.
* Max in ''Literature/MaximumRide''. She's normally a calm and easy-going person. However, she treats the flock like her own brothers and sisters. If you're foolish enough to [[TemptingFate threaten one of them]], you're gonna regret it.
* Thresh in ''Literature/TheHungerGames'' seemed to take Rue, the girl from his district, in as a sister because when she died, he was infuriated by her death. During the feast, Thresh overheard Clove talking about Rue to Katniss. Thresh grabbed Clove off Katniss, strangled her while holding her one foot off the ground, and yelled at her about Rue. He then kills Clove to avenge Rue.
* You do NOT mess with [[Literature/TheDresdenFiles Thomas Raith's]] siblings, not even if you're their father. Especially his younger sibling[[spoiler:s Inari and Harry (who, though younger, reciprocates the sentiment as the RelativeButton is a pretty big frickin' deal to him)]].

[[folder:Live Action TV]]
* ''Series/GameOfThrones'': Jaime seems to be one of the very few people who genuinely loves and cares for Tyrion, and he thus reacts badly when Tyrion's safety is threatened. Cersei also mentions that he would have killed Robert if he found out about the DomesticAbuse in "You Win or You Die". He also refuses to kill Tyrion when Cersei asks him to after Joffrey's death.
--> '''Jaime:''' He's my brother. He's ''our'' brother.
** It doesn't appear to apply to anyone who's not his immediate blood relative, for his younger, (and admittedly distant) cousin, the worshipful and friendly Alton Lannister, was cruelly killed by Jaime, so in order to escape captivity.
* [[Series/TheXFiles Scully's big brother]] Bill. It's really annoying, since this is a woman who has been shown to be able to handle herself time and time again amongst a predominantly male-oriented workplace. She goes out of her way to never be accused of special treatment because she's a woman. And yet she lets Bill push Mulder around all the time.
** It's not all the time. Bill and Mulder meet about twice in the entire course of the series, and though Bill bad-mouths Mulder, the fights between the men usually happen when she's not around. Not to mention Mulder is capable of holding his own in those fights. The annoyance of this trope comes more from the fact that Bill is making assumptions with half the story.
** Also slightly justified when it comes out that Bill has always acted like this as a result of having to be "the man of the house" when his father was away at sea, and that Dana has always taken his opinion with a grain of salt. It's not only Mulder Bill has a problem with, but her having a life different from what was expected of her: joining the FBI rather than practicing medicine, not getting married, [[spoiler: having a child out of wedlock]]...Mulder is only a part of it, though a substantial part.
** And though his little sister is gone for the entire series, Mulder could most definitely count. He's spent his entire adult life searching for and avenging his sister's kidnapping. Samantha Mulder is the reason Mulder works on the X-Files and why he is so determined to uncover the conspiracy. He does not hesitate to hurt or kill someone in the process of finding her.
* BigBad Kanzaki Shirou from ''Series/KamenRiderRyuki'' very definitely fits this trope.
* ''Series/{{Supernatural}}'' has the Winchester brothers. ''Both'' of them.
** If you ''think'' of putting a even ''single finger'' on Sammy, you should be fist ''and'' gun proof. Or, if you're an angel, [[ShameIfSomethingHappened messing]] with [[AndYourLittleDogToo Sam]] to get Dean's agreement is a [[BerserkButton very bad idea]].
** After making Sam watch Dean die over a hundred times in one episode to try to desensitize Sam to losing Dean (it doesn't work; after Lilith kills Dean, Sam turns to TheDarkSide for vengeance and the power to [[UnwittingPawn save the world]]) the Trickster[[spoiler:/Gabriel]] comments that:
-->"Whoever said Dean was the dysfunctional one has never seen you with a sharp object in your hands."
** You probably don't want to mess with Castiel on Dean's watch (or vice versa) either, although they are more like unofficially adopted siblings
** Lucifer and Michael might have been trying to destroy one another, but Lucifer got pretty vengeful when Castiel Molotov'd Michael.
* ''Series/{{Firefly}}'': Don't mess with Simon's little sister. Just don't. And don't mess with River's big brother. [[CurbStompBattle Pity the poor Reavers]].
* No matter how he tries to negate it, ''[[Series/{{Chuck}} John Casey]]'' seems to take that road in regards to Chuck, even though he always claims it's to protect the Intersect. The Casey Doth Protest Too Much, indeed.
* It is revealed in one episode of ''Series/MalcolmInTheMiddle'' that Reese is this to Malcolm, and that was the only thing keeping him from getting beat up for his smart mouth. Malcolm finds this out when his brother decides to be nice for the rest of his life.
* Don Eppes of ''Series/{{NUMB3RS}}''. Not just towards Charlie, even (although Charlie is definitely the primary trigger for this). Don behaves like this towards the team in general.
** "Trust Metric": When given a choice between boarding a foreign ship illegally and possibly letting Colby die, the ''only'' question Don poses to make the choice is whether Colby's death is a likely outcome or not. The fact that a rescue operation would require breaking international law is clearly not relevant to him.
** Watch very carefully when Don blows up at Nikki in "The Decoy Effect". It's not the case he's worried about, it's that Nikki could have been hurt or killed.
* Justin, from ''Series/WizardsOfWaverlyPlace'', tells his younger sister, Alex, that he always thought he would intimidate her boyfriends if they got out of line, and in "Wizards vs. Werewolves" he fights Mason (who is in full werewolf mode) for her ''with his bare hands''.
* Don't get in between [[Series/{{Carnivale}} Iris Crowe's]] little brother and...anything. Just don't.
* ''Series/BurnNotice'':
** ''Do not'' pick on Nate, Michael Westen's little brother. It is unhealthy. [[spoiler:As those involved with Nate's assassination in season 6 discovered]].
** In the episode "Comrades", there is a deconstruction. Michael meets a Russian woman named Katya whose little sister Elena is kidnapped by the Russian Mafia. Michael has to convince her that being a vengeful big sister might not actually be in the little sister's interest.
* ''Series/PrisonBreak'': Don't mess with Linc or Michael will come up with an elaborate plan to destroy you. Don't mess with Michael or Linc will kick your ass.
* ''Series/MrRobot'': Even if she is his younger sibling, Darlene will not let anyone manipulate and hurt her older brother Elliot and use his mental illness against him. She was slightly mad at Angela, whom Elliot was in love with for using his split personality for Stage 2 plan and working with the Dark Army behind their backs.
* ''Series/BuffyTheVampireSlayer'':
** Buffy warns her friends in the season 5 finale that she will kill anyone who tries to lay a hand on her little sister, [[BarrierMaiden Dawn]], TrueCompanions included, even though Dawn's death [[AlwaysSaveTheGirl might prevent the apocalypse]], and Dawn is [[CosmicRetcon a magical creation]] [[YoungerThanTheyLook only a few months old]] instead of a natural-born sibling.
** In Season 2, Willow is kidnapped by a group of vampires looking to revive [[BigBad The Master]], intending to use her (and a few others) as a human sacrifice. Xander, who blames this on Buffy being depressed and distracted after being clinically dead, threatens to "kill [her] myself" if Willow isn't rescued unharmed.
* Jing Tian from ''Chinese Paladin 3'' boomerangs from having a simple BigBrotherInstinct to full on Knight Templarhood. For example, his reaction on seeing his best friend "threatening" his little sister with a HealingShiv is to attack and nearly kill him.
* Cesare [[Series/TheBorgias Borgia]] is this to a somewhat frightening degree in regards to his younger sister, Lucrezia. By the third episode he's threatening to cut her husband-to-be's heart out with a dinner knife if he's "ungallant". He shows some signs of this towards one of his younger brothers, Gioffre. [[CainandAbel Not so much with Juan.]]
* In {{Series/Arrow}}, Oliver's sister Thea takes a new drug called Vertigo and drives under the influence due to family issues. So Oliver does the reasonable thing and visits her in the hospital, and then he tries to support her legally, especially after the judge wants to make an example of her, and tries to help resolve the family issue that led to the car crash. So why is this entry here? Because he also [[spoiler:tracks down the drug lord that made the drug and sells it, known as The Count, and injects him with the very drug in its purest form in an insanely large quantity, leaving him insane due to the drug making him imagine being in the most excruciating pain possible. The episode ends with him spasming violently and screaming strapped to a hospital stretcher as a doctor explains his extreme condition.]] And he never got NEAR Thea, only being an indirect cause!
* ''{{Series/Friends}}'' - Ross attempts to be this to Monica after she got engaged to Chandler, stating that if Chandler ever hurt her, he was going to "...hunt him down, and KICK HIS ASS!". The rest of the friends (including Chandler himself) found this hysterical.
* On ''Series/{{Youngers}}'', Jodie's brother is this. He threatens to beat Jay up for just looking at her and when Jay breaks up with her, she tells him, which leads to a beatdown.
* At six years old [[Series/SonsOfAnarchy Abel]] is shaping up to be one that would make even Buffy the Vampire Slayer herself scared: after learning Gemma killed his mother he attacks another boy, claiming it an ''accident.'' He is caught swinging a hammer around to protect his younger brother Thomas. When Gemma is given birds as a gift he takes a page from [[Series/TheGodfather Vito Corleone]] and kills them before putting them in her bed, then goes one step further by stabbing his toys and painting threats on the wall. And to top it off he reveals to Jax what happened.


[[folder:Myths and Religion]]
* Absalom from Literature/TheBible, who learns that his sister Tamar was raped and humiliated by their half-brother Amnon and, instead of telling their father David to demand punishment, he goes and kills Amnon himself.
** In all fairness, David was already well aware of what had occurred (see 2 Samuel: 22-23). His response was to be 'very angry'... and do absolutely nothing. Absalom decided to take justice into his own hands - it was obvious none was forthcoming from their father, the king.
* In a similar incident, two of the sons of Jacob killed everybody in a village for mistreating their sister. Presumably they wished the feud to [[LeaveNoSurvivors end right away]].
** To put it into perspective, Jacob's daughter Dinah had been raped by a prominent member of the village who fell in love with her. Despite the circumstances, he and his father wanted to smooth over relations with Jacob's family and offered to pay for her dowry as if she'd still been a virgin, [[ValuesDissonance which was actually quite a generous offer at the time]]. Jacob seemed to warm up to the offer, but his sons demanded that all the men of the village circumcise themselves to become part of Jacob's tribe. The men agreed, with the idea that they would now be able to intermarry with Jacob's tribe. After all the men were circumcised and helpless, though, Dinah's brothers took advantage of the situation and slaughter the entire village, taking only women and children alive as slaves. When Jacob [[WhatTheHellHero criticized them for the actions]], saying that no one would trust him now, they only replied: [[MyGirlIsNotASlut "Our sister should not be treated like a whore."]] Jacob went along with this right up until just before he died, at which point he called them in and disinherited them for wiping out an entire village for the actions of one man. (Historians believe this story was written in part to explain why those tribes of Judea were on the bottom of the social ladder.)
* In The ''Literature/{{Mabinogion}},'' Efnisien gets very angry when his half-sister, Branwen, is married to the king of Ireland:
-->''And thereupon he rushed under the horses and cut off their lips at the teeth, and their ears close to their heads, and their tails close to their backs, and wherever he could clutch their eyelids, he cut them to the very bone, and he disfigured the horses and rendered them useless.'' And this is just his initial reaction.
** And when Branwen's husband starts treating her like a slave, all her brothers go to war to defend her honour.
* Apollo of Myth/GreekMythology tricked his sister Artemis into killing her almost-LoveInterest Orion because he didn't want her to break her vows of chastity. (Though technically, he's her younger twin.)

* The filecards for Franchise/GIJoe members Barrel Roll and Bombstrike, and the filecard for Cobra operative Blackout contain a story where Barrel Roll acts as Knight Templar to rescue his sister Bombstrike after blacksheep brother Blackout kidnaps her.

[[folder:Video Games]]
* Gulcasa of ''VideoGame/YggdraUnion''. Serious harm befalling his younger half-sister Emilia induces BerserkButton-level rage, and towards the end of the game--directly after he learns [[spoiler:that she has been killed by the Royal Army]]--said rage causes him to reject Yggdra's repeated pleas for a cease-fire to the war that has [[spoiler:''effectively destroyed most of his country'']]. Usually, he's a shrewd and reasonable ruler, but in this case...
** Emilia actually inverts the trope in one of the routes of ''VideoGame/BlazeUnion'' where Gulcasa never discovers his powers (or that they're related), and purposely risks going permanently AxCrazy in order to get the power to protect him and the rest of her adoptive older siblings in Gram Blaze. On the chance that she actually does go insane, [[spoiler:Gulcasa is left StakingTheLovedOne, after which he [[HeroicBSOD crawls into his]] [[Anime/NeonGenesisEvangelion Shinji corner]] [[DespairEventHorizon and doesn't come out]].]].
* Don't get anywhere near ''VideoGame/TheLegendOfZeldaTheWindWaker'' 's Aryll, or prepared to be mercilessly hacked into pieces by the Master Sword. Good thing Link's an only child in all of the other games.
* [[HandsomeLech Zelos Wilder]] in ''VideoGame/TalesOfSymphonia''. Though Seles seems to hate him for being born [[spoiler:since her mother tried to kill him so that Seles could be TheChosenOne instead, but Zelos' mother [[TakingTheBullet saved him]], and as a result Seles' own mother was executed]], he will "throw anyone who so much as looks at her wrong down the Palmacosta harbor". Whoa, dude, chill.
** [[spoiler: [[BigBad Mithos Yggdrasil]] from the same game. [[EvilPlan He split the world into two and caused everything that leads up to the main plot.]] His goal? To resurrect his sister Martel.]]
** Guy Cecil from ''VideoGame/TalesOfTheAbyss'' -- his older sister Mary [[spoiler: may be dead]], but he practically raised Luke. Guy's a pretty chill person normally, but if you so much as threaten one hair on Luke's head, you press his BerserkButton. Especially evident during the Summit, when [[spoiler: Jade suggests Luke die in Asch's place, and Guy ''grabs Jade by his collar'', actually ''yells'', and calls Jade a bastard for it.]]
* In ''VideoGame/TalesOfXillia2'', this ends up being inverted [[spoiler: if you choose to see the bad ending by making Ludger refuse to kill his older brother Julius (Something the latter wants, as he's doomed, and it's the only way to extract a Soul Bridge from him, a key that the party needs to save the world). Gaius proceeds to state that he'll do the deed himself, then things get ugly from there. ''[[KillEmAll Really ugly.]]'']]
* [[spoiler: Beat]] from ''VideoGame/TheWorldEndsWithYou'' makes a FaceHeelTurn in reaction to [[spoiler: Rhyme getting erased; he becomes a Reaper in the hopes of restoring her to life.]]
* Targeting [[VideoGame/Disgaea2CursedMemories Axel's]] little brother is not a good idea, something a repo man learned the hard way at the end of the Axel story. And as aforementioned Dark Hero learned the hard way, do not abduct Adell's siblings or Rozalin's "servants". ''For any reason at all''.
** The plot of ''VideoGame/DisgaeaDimension2'' can be summed up as this given that [[spoiler: Xenolith would allow the Netherworld to transform into something similar to Celestia as well as give up his life if it means saving his little sister Etna. Alas Etna constantly refuses to acknowledge that Xenolith is her older brother even with her life on the line. Of course one particular bad ending has Xenolith fail to save Etna when she refuses to acknowledge that Xenolith is her older brother and destroys the artifact that is destroying the Netherworld with her powers in it. That power ends up killing her and everything he has done had been for nothing.]]
* And let us not forget that ''VideoGame/MegaMan'' and Proto Man are basically teaming up together in ''10'' to get the vaccines for Roboenza, to cure Roll. Hell Mega Man goes after Wily before he goes after the Robot Masters. Whoever created this virus better have good life insurance. [[spoiler:Yeah, Wily's life insurance is up to date. [[JokerImmunity Bastard]]'s ''[[JokerImmunity still]]'' [[JokerImmunity alive]].]]
** Blues in ''Manga/MegaManMegamix'' fits the 'morally questionable actions' part of the trope (what separates it from BigBrotherInstinct), up to and including ''threatening to kill Kalinka Cossack'' if anyone gets involved in [[spoiler:the MirrorMatch between Mega Man and Copy-Mega Man]]. Of course, [[spoiler:not only was there the risk that they'd shoot the wrong one if they'd tried to help, but Dr. Wily had given Shadowman orders to take advantage of the chaos to kidnap Kalinka. Blues couldn't help Mega Man fight without letting Kalinka get snatched, and he needed some way to keep the other robot masters present from trying to help Rock and causing the FogOfWar Wily was going for. If he hadn't threatened her, they would have tried to go through him, and Shadowman would have taken her while he was distracted. By the side of the one with the ''shield'' was the safest place for a human among a lot of robot masters with itchy trigger fingers, and]] he did succeed in saving everyone [[spoiler:except Copy-Mega Man.]] There are plenty of other examples.
** Consider that Wily based his own robot designs on Proto Man's specs. Bass would then be multiple inversions of the trope: he's on a constant mission to destroy Mega Man, and if Wily pisses him off he'll gladly take it out on the other Wily bots...who are also Proto Man ripoffs.
** Any attempt to harm VideoGame/MegaManX or Zero in the other's presence will result in the survivor of the pair ''bringing the BigBad's fortress down on top of you.'' In later games, if you take out Axl, you now have to deal with TWO pissed-off Knight Templar Big Brothers.
* ''VideoGame/{{Prototype}}'': Whatever happens, whoever you are, whatever the reason, never ''never'' '''never''' harm Dana Mercer in any way, because the consequences for doing so come in the form of her big brother, Alex. Alex is a shapeshifting, superstrong, superfast, superagile, incredibly resilient HumanoidAbomination with ''[[UnstoppableRage issues]]'', and Dana is the [[MoralityPet one thing in the world he cares about]]. Alex once prevented Dana's capture by punching ''through'' the torso of a soldier wearing body armor. Alex [[ImAHumanitarian ate]] a few dozen people who [[BrainFood happened to be vaguely connected]] to Dana's location when kidnapped, and two monsters, and the mastermind herself. [[MindHive Alex is already]] [[LovecraftianSuperpower not wholly stable]]. Try something safer, like playing Chicken with the sun. [[spoiler:And in a wholly depressing twist, Alex isn't even really Dana's brother, simply a virus wearing her brother's corpse like a suit. The real man cared so little about his younger sister that he ''knowingly'' condemned her to a hideous death with the rest of the world when he released the virus, before he died and it consumed his remains. This was a man so devoid of love that a flesh-eating virus designed specifically to wipe out humanity cares for his sister more than he did. [[MoralEventHorizon What a dick.]]]]
** In the [[Videogame/{{Prototype2}} sequel]], [[spoiler: Alex appears to have dropped this trait, [[RogueProtagonist alongside almost any positive traits he had]]. Though it should be noted that despite Dana working against his evil plan, he chooses to capture her, rather than just kill her like he did Heller's other contact, Father Guerra.]]
* It's implied that Joel from ''VideoGame/TheLastOfUs'' was this for his younger brother, Tommy. Considering that they've spent the last twenty years living in a ZombieApocalypse and Joel lost his daughter within the first hours of the outbreak, you can't blame him for being scared. However, it's implied that Joel did much more than kill people and Infected.
* In ''VideoGame/{{Persona 4}}'', acting this way and [[spoiler:throwing Namatame into the TV after Nanako's apparent death]] will get you [[NiceJobBreakingItHero the worst ending]].
** PlayedForLaughs in ''VideoGame/Persona4Arena'', where Yu is given the EmbarrassingNickname "The Sister Complex Kingpin of Steel".
* Axel of ''Franchise/KingdomHearts'', towards Roxas. He raises the amnesiac keyblade-wielding Nobody... but he's also a ''really'' PoisonousFriend.
* In ''VideoGame/GrandTheftAutoSanAndreas'', [=CJ=] finds out that some construction workers have been calling his sister Kendl a hooker. Not only does he bust up the portables at the construction site, but he also traps the foreman in a porta-potty and [[DisproportionateRetribution uses a cement mixer to]] ''[[BuriedAlive bury him alive]]''. And all the while, the poor guy is screaming [[CrossesTheLineTwice "OH GOD, WHY?!"]]
* ''VideoGame/DirgeOfCerberus'' messes with this. It's actually the little brother, Nero, who goes completely batshit when his big brother is threatened.
* [[spoiler:Albus]] in ''VideoGame/CastlevaniaOrderOfEcclesia''. [[spoiler:Pretty much does everything he can to protect Shanoa in the first half of the game, going so far as to appear a villain for it, until Barlowe is outed, anyway.]]
* The protagonist of the [[NoExportForYou Japan-only]] ''VideoGame/NieR Replicant'' is TheUnfettered when it comes to protecting his sister Yonah (in the Western version, he's instead a PapaWolf).
* [[HotWitch Konoe A. Mercury]], better known by her nickname "Nine", of ''VideoGame/BlazBlue'' is one of the Six Heroes who battled and defeated the [[EldritchAbomination Black Beast]]. And she happens to be fiercely protective of her baby sister Celica. If she so much as senses that you even consider causing trouble for her (and yes, [[DisproportionateRetribution being a male]] is enough), don't be surprised when she roasts you with her magic. Worst case scenario, you are blown to oblivion by one of Nine's creations, the GODDAMNED Nox Nyctores KillSat Take-Mikazuchi, which is exactly what she did to the Beast.
* In ''VideoGame/DragonAgeII'', the player character can act like this towards their younger sibling, Bethany or Carver. And considering what can potentially happen to them throughout the game, including ''the inevitable death of one of them'', it's no wonder.
** It's much more prominent with Bethany, however, such as when Ser Wesley identifies Bethany as being an apostate in the prologue, causing Hawke to [[EstablishingCharacterMoment immediately]] step [[BigBrotherInstinct in front of her]] and stare down the Templar with a DeathGlare. This even happens if Hawke is a mage, putting themselves potentially in the line of fire to protect her. [[spoiler: Should Bethany go to the Circle, Hawke similarly threatens to disembowel any Templar who touches her, only relenting when Bethany explains she's going peacefully and by her own accord]].
* A possible sidequest in ''VideoGame/TheGodfather 2'' involves you being told to beat up or kill someone taking advantage of the quest-giver's sibling.
* In ''VideoGame/{{Borderlands 2}}'', it's implied that Scooter acts like the trope towards his sister, Ellie, despite Ellie telling Scooter to leave her alone and stop setting her customers on fire.
* In ''VideoGame/UntilDawn'', [[spoiler:Josh turns out to be this. Ever since his sisters' tragic deaths, he went into a great depression and was even went through a major SanitySlippage. The whole reason for the return to Blackwood Pines lodge was just to get revenge against those whom he blamed for Hannah and Beth's deaths. Depending on the choices made by the player, he may succeed in getting his revenge.]]
* The Big Sisters from ''VideoGame/BioShock2'' are the embodiment of this trope. To make matters worse, they are incredible fast, can easily kill you with a few hits, have a lot of health, climb walls, plus they often make mooks spawn and occasionally flood the area which results in visual impairment. They are the reason why most players were happy when the fight for a Little Sister was ''only'' against a [[PapaWolf Big Daddy]].
* In ''VideoGame/CallOfDutyBlackOps2'', [[BigBad Raul Menendez]] is willing to bomb Los Angeles and start a world revolution that could get millions of innocent people killed to [[spoiler:avenge the ''accidental'' death of his sister Josephina at the hands of Woods.]]
* Elro in ''VideoGame/{{Iconoclasts}}'' was already protective of Robin from the start due to the passing of their father, but he takes it too far after [[spoiler:his wife and daughter are killed]] and Robin decides to keep fighting One Concern against his wishes. His aggressiveness and refusal to do anything that would put Robin in danger (even though Robin is much stronger than him) makes him the TheMillstone of the party, resulting in him trying to take on TheDragon alone by locking himself in with her (this gets [[spoiler:his arm ripped off]] and scatters the party across the world) and being very uncooperative in a plan that’s vital to ''saving the planet''. [[spoiler:The cruel irony is that, while he never admits it, Elro is the initial cause of all the dangers Robin goes through; before the game started, he performed a petty act of rebellion against One Concern, whom he blamed for his father’s death, and the resulting scheme killed off one of One Concern's agents and caused another (Agent Black, the aforementioned Dragon) to become hell-bent on getting revenge on Elro and his family.]]

[[folder:Visual Novels]]
* ''Franchise/AceAttorney'':
** Phoenix Wright is like this with Maya Fey, his assistant and the little sister of his dead mentor Mia. Since this can sometimes be thought to be a ShipTease by some fans, it is noticeable that he would run across a ''burning bridge'' to save her from a cave, and break down a door that led to her after hearing a gunshot in the room. And Maya is also this way towards her cousin, Pearl, as she was enraged when Phoenix suspected her of any wrongdoings in the second game.
** The Blackquill siblings from ''Dual Destinies''. Younger brother Simon is this towards Athena Cykes (though again this can be seen as ShipTease by some), as [[spoiler: he went through death row [[TakingtheHeat for her sake]] when she was mistakenly accused of {{matricide}}]], was willing to threaten Phoenix in court if he tried to prove her involvement in a case, and [[spoiler: kept insisting that ''he'' killed Athena's mother even when he'd be executed for it, if that meant he'd keep protecting Athena.]] Same with older sister Aura, [[spoiler: who held an entire building of people hostage to allow her brother to be acquitted from false murder charges.]] Guess this runs in the family.
* Clover in ''VisualNovel/NineHoursNinePersonsNineDoors'' has a suspicion on who killed her older brother, Snake, in Door 3. In the Axe Ending, when she calculates who the murderers are, she acts on said misconception, [[spoiler:killing both Santa, Seven (the suspected murderers) and June for defending them, before turning against the protagonist himself]]. Though depending on how well the game is played, the players can get the True Ending, where Junpei befriends her and inadvertently stumbles across a crucial clue that indicates [[spoiler:her brother is still alive.]]
* [[spoiler: Kaoru "Sou-Banchou" Ichimonji]] from ''VisualNovel/TokimekiMemorial 2'' is revealed to be this if you romance his younger sister, [[spoiler: Akane]]. And this is [[spoiler: ''the main character's own fault'': Sou-Banchou witnessed first-hand [[LoveHurts how utterly heartbroken]] [[HeroicBSOD the poor girl was]] was when you-as-the-MC moved outta the city, so he swore to pretty much punch the HELL outta any guy who made her cry.]]
* Both Keiichi Maebara and later, [[spoiler:Shion Sonozaki]], from ''VisualNovel/HigurashiWhenTheyCry'' fall prey to this syndrome when their non-blood-related "sister", little Satoko Houjou, is {{abus|iveParents}}ed [[EvilUncle by her uncle]]. Winds up leading to some of the most tragic endings of the games. It is also implied that her [[spoiler:actual brother, Satoshi]] did the same regarding the [[AbusiveParents aunt]].

[[folder:Web Comics]]
* Johan of ''Webcomic/AndersLovesMaria'' has long been violently protective of his little sister, Maria. Leads to him committing acts of vandalism and assault in her name.
* Mijuu of ''Webcomic/{{Juathuur}}'' is Dejoru's overprotective big sister.
* ''Webcomic/{{Panthera}}'' has Jason, who threatens his best friend Fletcher (who finally got a date with Taylor) as such:
--> '''Jason:''' If you do '''''ANYTHING''''' to her, in '''any way, shape or form''', I will quite literally '''#%$&!$# EAT YOU'''. And you have '''NO''' idea just how '''DEEP''' I could '''BURY''' what'd be left of your sorry '''carcass'''. '''UNDERSTOOD?'''
* Hayden in ''Webcomic/TheStoryOfAnima'' is normally calm and sensible, but when his already badass sister Ada is even remotely threatened, [[http://tapastic.com/episode/49413 he slices the attacker's arm off]].

[[folder:Web Original]]
* ''WebAnimation/BrokenSaints'': Tui Jr, adoptive brother to HeartwarmingOrphan Shandala, can resemble this at times, due to his being so hot-blooded.
* Lenny Priestly of ''Roleplay/SurvivalOfTheFittest'' v3 will do ''anything'' to make sure his twin sister Elizabeth is safe. Literally anything, as he kills people for this reason. Though possibly a subversion, as it has been implied that he used her as an excuse to kill, especially since he went AxCrazy and stopped being an AntiVillain.
* In ''Literature/DeadWest'', Cedric, big time. His finer moments include burning several churches (only the first was warranted), and dropping a teenager into a huge, steam-powered meat grinder. Feet first. He kind of deserved it. And the way he killed his best friend for molesting his little brother belongs to the NightmareFuel page.
* In ''Literature/{{Brennus}}'', Amy is very ''very'' protective of her younger brother Basil, although she doesn't tell him about everything she does. He still thinks [[spoiler: some of the Hemogoblins]] got away. She tore them limb from limb.

[[folder:Western Animation]]
* Dee Dee from ''WesternAnimation/DextersLaboratory'' may appear to be a [[TheDitz flake,]] but you do NOT harm her little brother. Or she will kick your ass.
* While they're on separate sides, Protoman from ''WesternAnimation/MegaMan'' certainly fits. No one, save Protoman himself, is allowed to touch Mega Man -- not even Wily. True, he [[TheOnlyOneAllowedToDefeatYou states that wants to defeat Mega Man himself]], but [[WeCanRuleTogether not really]].
* Kenny [=McCormick=] from ''WesternAnimation/SouthPark'' displays this in the episode "The Poor Kid". If you have the gall to mess with Karen [=McCormick=], Kenny proves that he WouldHitAGirl [[NoHoldsBarredBeatDown quite viciously]], as Jessica Pinkerton finds out. The rest of the school gets the hint that the girl is off limits.
* Dipper Pines from ''WesternAnimation/GravityFalls'' can be this. Though he and his sister Mabel are twins (and he's the younger one), [[BewareTheNiceOnes he is perfectly willing to extract some revenge on those who wronged her]]... even if she doesn't want revenge herself.