Then the Lord said to Cain, “Where is Abel your brother?” He said, “I do not know; am I my brother’s keeper?” And the Lord said, “What have you done? The voice of your brother’s blood is crying to me from the ground."
In Area 88, the Asran civil war was started by two royal brothers — King Zak and Prince Abdael — with different visions for the future of their country. Tensions erupted years before the conflict, when their father chose the younger brother (Zak) to succeed him.
In Axis Powers Hetalia, the characters of China and Japan enact this trope in their Back Story, with China as the Abel (despite being the elder) and Japan as the Cain. Japan was raised by China as his younger brother, yet never really considered himself his brother, and in the end he injures China with his katana and abandons him. Even when they're shown later to be in more civil terms, the bad blood is not exactly gone.
The character of "Korea" represents only South Korea, due to the obvious Real Life issues surrounding the two countries in the peninsule. When fanworkers create an Original Character representing North Korea (sometimes male, sometimes female), they and South Korea end up recreating this trope as well.
Fanon characters 2P!America and 2P!Canada are generally depicted like this, too, with 2P!Canada as the Abel to 2P!America's Cain.
Baccano! features a story arc centered around Eve Genoard desperately searching for her older brother Dallas. She frequently puts herself in severe danger for his sake, all the while proclaiming her devotion to him and her belief that he's a wonderful person. Meanwhile the audience sees through flashbacks that Dallas is actually the story's premier Jerk Ass, who mostly spends his time running around being a huge dick to EVERYONE he meets. Including Eve.
In Blood+, a natural scientist finds Saya and Diva's mother's corpse and hatches the infants from their cocoons (it's complicated). As part of an experiment, he raises Saya as his own daughter and locks Diva in a tower to be a guinea pig. Saya is raised as a normal human girl; Diva is experimented on and denied anything more than a blanket and a meager amount of food. Saya grows up seeing humans as equals; Diva grows up seeing humans as torturers and also food. One day Saya meets Diva and lets her out. The resulting bloodbath started a conflict between the two sisters that lasted for over a century.
Blue Exorcist: The tragic aspect of this almost happens to Rin (Hot-BloodedAnti Anti Christ) and Yukio (genius exorcist and Rin's younger twin brother) when the former discovers he's the son of Satan and then learns that the latter knew it all along and now wants to kill him (they get better) but there are still hints that Yukio is more susceptible to the dark side.
Secondary case with the other two sons of Satan Mephisto Pheles (AKA Johann Faust V) and Amaimon: Mephisto is outgoing and clownish (similar to The Millennium Earl, complete with umbrella) while Amaymon seems to be quieter and darker.
To further contrast, Mephisto seems much more careful and meticulous - even if he seems to just be having fun most of the time. Amaimon seems rather reckless and immature, with Cloud Cuckoo Lander tendencies. Also, while both brothers seem to get along fairly well, they do clash at one point: Amaimon wants to keep fighting Rin, even after they've begun doing damage to the school grounds, and even though Rin is beginning to go Berserk from Satan's flames. Mephisto does not like this, and promptly intervenes. He is able to restrain both Rin and Amaimon at the same time, explaining to Amaimon why they had to stop fighting. But Amaimon wouldn't listen, and punches Mephisto in the face mid-sentence. Mephisto's retaliation is hilarious. Amaimon has not been seen since but, chances are, these two aren't going to be getting along so well when Amaimon gets out of that Kuchen Cuckoo House.
Amaimon has been seen twice again; first time He delivers a Curb-Stomp Battle to Rin before Rin gets pulled away as a "lesson" from Mephisto to Rin. The second time he's seen at the end of chapter 44 with a bunch of sticks/spears stabbed through him and holding him up in the air. Mephisto tells him he's not getting out until he doesn't want to kill Rin anymore.
Aion and Chrono, as they often seem to be even more than brothers...in the manga Aion and Chrono were close friends and described as "like brothers"—demons in the series are Bee People and don't exactly have the concept of family. Except Chrono and Aion were turned into demons when their (human) mother was pregnant with them—they're twins. Aion is rather obsessed with getting Chrono back on his side, although when he refuses Aion gleefully tortures him for it. The anime version makes the pair have a more distant relationship, but also implies that they're two sides of the same coin. (Not to mention giving the pair their fair share of Ho Yay.)
Meanwhile, Rosette made a contract with Chrono in order to save her brother, Joshua, after he was kidnapped by Aion. It turns out that Joshua is radically devoted to Aion (partially because he's been given power that drives him mad), which causes the pair to fight...when Joshua remembers Rosette is his sister at all.
Satella reveals early on that she's searching for her missing sister.Guess who also happens to be working for Aion? Her sister Florette, now called "Fiore". When this is revealed the pair naturally ends up fighting each other.
Code Geass: Lelouch and Suzaku, in the childhood friends variety, although for a while they aren't even aware they're on opposite sides. It kicks into high gear after the Wham Episode, though, when one of them ends up killing someone they both loved. Not only that, but the whole driving force behind the plot is Lelouch's revenge-fueled crusade to slaughter almost his entire family aside from his little sister.
As well as destroy and recreate the world so that his sister never suffers again.
And again when said little sister finds out and tries to stop him.
In Corsair, Jean-Hughes blamed Canale for everything that went wrong with their family and tried to kill him several times as a child (thinking he succeeded). When he finds out Canale is, in fact, still alive he continues to plan to do him off. While Canale has a lot of blood on his hands at this point, Jean-Hughes is clearly the "evil" brother and in the end Canale kills him instead.
In Cain Saga, Earl Cain is, ironically, the Abel to his psychopathic and illegitimate elder half-brother Jizabel.
Agon and Unsui of Eyeshield 21 seem to be set up as this at first, with the younger sibling being blessed with unlimited talent and the elder having to suffer hellish training just to be half as skilled. However, while there's definitely some tension between them, the older brother ends up being more dutiful to the younger rather than hateful.
Fist of the North Star: The villains, Raoh and Jagi, are the series's Cain to Kenshiro and Toki's Abel. Though Kenshiro and Jagi's relationship is more direct (with the former killing the latter instead of the other way around), Raoh subverts this. While he defeated Toki in combat, Raoh sheds enormous amounts of Tender Tears, knowing his condition due to radiation sickness. Raoh and Kenshiro also has their first and final battles. While the first fight between the two is seemingly played straight, the final one isn't. Raoh held his brother's face like a true big brother after his defeat.
Raoh and Toki/Kenshiro of Fist of the North Star. Also, Jagi and Kenshiro. At least Raoh had standards and respected Kenshiro. Jagi's intense hatred for Kenshiro instead turned him into a monster, whereas Raoh was more of a Noble Demon.
In the Fullmetal Alchemist anime, the homonculus Envy turns out to be the result of attempted resurrection of Hohenheim and Dante's son, making him Ed and Al's older (by a few hundred years) brother. This is foreshadowed repeatedly through the series, with much of Envy's actions being a result of his, well, Envy of Ed and Al for being their father's favourites, as well as a burning hatred for his father. Envy even ends up killing Ed (albeit temporarily) like the Trope Namer, for bonus points in this trope.
The trope is in action in a truly bizarre way in the manga andBrotherhoodanime, where Big BadFather was created from Hohenheim's blood, making him Ed and Al's spiritual and biological brother, and his children, the Homunculi, their nieces and nephews.
Another childhood friends one: Miaka Yuuki and Yui Hongo in Fushigi Yuugi.
GaoGaiGar has the champion of the G-Stone, Gai, and the champion of the J-Jewel, Soldato-J. Bonus points because the respective developers of the G-Stone and J-Jewel were actually named Cain and Abel.
It's actually more of an aversion of the standard formula. Cain and Abel weren't related (instead the leaders of their respective planets) and there was never any animosity between them. Cain harnessed the power of the G-Stone and created Galeon to protect his son Latio (aka Mamoru) and fight the Zonders. Abel thought Cain was on to something and used the J-Jewels to create Arma and the J-Cyborgs/Arks. Plus, J only awakens his J-Jewel powers after he makes his (sort of) Heel-Face Turn.
Kagura and Kamui of Gintama, estranged siblings who would probably have gotten along were Kamui not such a jerkass (trying to kill your dad then disappearing for years is not the way to forge strong family bonds). As it is, Kagura considers all their bonds severed and Kamui seems to want little to do with her.
Glass Fleet: Vetti and Cleo. Though they don't know they're related until the very end of the series, combining this with the Separated at Birth trope.
In God Mars, the relationship of Takeru with his brother Ma, which fate would have it, pitted the two against each other in the war.
Gundam SEED gets Kira and Athrun, who're the childhood friends version. Unusual in that neither is really a villain, and both end up in a third faction after both sides they worked with turn out to be villainous. Though not before a climactic and nearly fatal final duel halfway through the series, naturally.
There's also Mu La Flaga and his father's clone Rau Le Creuset; one is The Ace, the other The Big Bad.
Kyouji Kasshu and his little brother Domon from G Gundam... Or so we think.
Ginias Sahalin from Mobile Suit Gundam: The 08th MS Team. We meet him as Aina's caring-but-aloof brother. Twelve episodes later we bid farewell an obsessive, murderous mad scientist who forces his once-beloved sister to pilot his giant mechanical monstrosity, tells her that "Love is an illusion', produced by your body's glands!", and then shoots her. (This is between blowing up/poisoning his allies, working his minions to death, and destroying perfectly good viewscreens.) She doesn't really object when her Main Character boyfriend tells her "Sorry, but I have to kill your brother now", even when she's not exactly happy either.
Higurashi no Naku Koro ni involves this with the twin Sonozaki sisters, Mion and Shion, as one of the two is the only one (besides those who already knew the whole story) who doesn't get infected with the Hate Plague, while the other, when infected, throws her conscience out the window even before she loses her mind and racks up the highest body count in the series besides the instigator herself. Yes, the elder is the "evil" one — the murderer was Shion pretending to be Mion most of the time, but because of a mix-up in their childhoods, the elder girl, originally named Mion, ended up living as Shion due to a Twin Switch, so Mion was pretending to be Shion pretending to be Mion.
As a result of Inuyasha claiming the sword Sesshoumaru's been pursuing for years, their Sibling Rivalry escalates into this trope for a while, mainly due to Sesshoumaru's belief that Inuyasha's claim proves he's The Unfavourite he's always secretly feared he was. This is eventually resolved.
Ginka and Kinka are from a youkai race where two heads (with associated identities and personalities) are born to a single body and one personality must kill the other (and devour the defeated head) before they reach adulthood because it's the only way their race can survive. Unfortunately for everyone, Ginka and Kinka have made it to adulthood, both alive, both still firmly attached to each other, and both still trying to kill the other. Their fight can lay entire villages to waste. It's so bad they even have to negotiate when they go to sleep and for how long just in case one takes advantage of the situation.
Tsubasa and Souma Ohgami from Kannazuki no Miko, though Tsubasa isn't really a bad guy and undergoes a rather spectacular Heel-Face Turn late in the series. What's more, technically, they are both Necks of Orochi, only that Souma has a good reason to fight against his "heritage".
Mawaru-Penguindrum: Kanba is the Cain to Shouma's Abel, largely because Kanba is in love with Himari, their (un)related sister and believes he has an obligation to protect her but Shouma saved her when she was younger (and he also saved Kanba when they met), and also disagrees about how Kanba has become more and more embittered, desperate and extreme in his methods in order to save Himari while Shouma is much more honourable and still believes things can be done without such extremes. It leads to QUITE the showdown, in which both guys get into a fist fight, before the last episode sees them face off.
There is also Masako who is an Abel herself to Kanba, as his twin sister who desperately wants him to come back home after he made a deal with their Disappeared Dad to protect Masako and their little brother Mario from danger.
Kanba in general is portrayed as a much more sympathetic version of Cain in general, as his reasons to be in such a position are less about his own benefit and more about genuinely but VERY misguidedly wishing to save Himari.
Tiger (older) and Gray Wolf (younger) in Monster Rancher. The roles are inverted with Tiger being the Abel to Gray Wolf's Cain. It's tragic because Tiger was a well-intentioned Aloof Big Brother who wanted to toughen his brother up. Unfortunately, this only fueled Gray Wolf's inferiority complex. And once Moo captures Gray Wolf, he magnifies these insecurities to the point Gray Wolf becomes a full-blown Green-Eyed Monster who wants to kill his own brother, much to Tiger's horror.
Michio Yuki from Osamu Tezuka's manga, MW, has this kind of relationship with his lookalike older brother, Tamanojo Kawamoto.
Naruto: Sasuke and Itachi Uchiha. To some degree, Hiashi and Hizashi Hyuga.
This can also describe the relationship between Naruto and Sasuke.
Temari and Kankuro felt this way about Gaara at first as well. Though in their case they weren't 'enemies' to Gaara so much as 'filled with mind-numbing terror' by him.
While they are cousins rather than siblings (although Hinata thinks of Neji as a brother) Neji is quite bitter toward Hinata and initially sees her as almost completely worthless until he loses to Naruto and rethinks his worldview. Some fan interpretations of Hanabi's relationship with her older sister Hinata apply this trope, typically making Hanabi the Cain.
Hinata and Neji's dads are identical twins, so genetically they're half siblings. Making this trope more obvious
Except no one thinks about genetics in the series, so, socially, they're still seen as cousins.
It's recently come out that, the history of the Uchiha clan and Konoha is based on this. Essentially the Uchiha and Senju clans are descended from the elder and younger sons of the first ninja. The elder Uchiha brother was the Cain whilst the younger Senju brother was the Abel.
It gets better. Turns out that these two men were the grandchildren of a princess who ate the forbidden fruit from the God Tree, much as the Trope Namers were the sons of Eve.
It gets even better. Those brothers' chakra reincarnates throughout the generations; first into Madara and Hashirama and then into,you guessed it, Sasuke and Naruto.
One Piece: Marshall D. Teach and Thatch. On the crew of the great pirate Whitebeard, all of his crew mates are considered his adopted children; likewise, they consider him "father," and one-another brothers. Since Teach and Thatch were crew mates, the former killing the latter players this trope surprisingly well.
Hana and Ageha from Papillon Hana To Chou: Hana is a popular city girl and a little manipulative while Ageha is plain country girl and walked all over. When Hana steals Ageha's potential love interest, Ageha is nearly Driven to Suicide. Their mom is a Well Done Daughter Gal to boot: Ageha was sent to the country because her constant crying aggravated her post-partum depression. As Ageha gains confidence she and her mom's relationship improves while Hana's behavior gets worse: Her latest scheme to ruin her sister's life caused Ageha's current boyfriend to break up with her, although they shouldn't have been together in the first place(eh, if he couldn't tell them apart he's probably not worth it anyway)
Princess Resurrection. All the royal siblings virtually are fighting to the death for the throne except for the main character Hime who has no interest in it.
Pops up in season 2 of Princess Tutu, when Mytho becomes tainted with Raven's blood and performs a Face-Heel Turn. Fakir is constantly forced to fight against him, even though they were practically raised as brothers.
It's hard to avoid in Rozen Maiden, where There Can Be Only One of seven sisters that survives (unless that cryptic statement at the end of season two has anything to say about it). Suigintou and Shinku in particular have exactly this relationship, although who is the betrayer and who is the good underdog switches around in different points of the timeline.
In Saint Seiya, Kanon (younger) and Saga (older). In the beginning, Kanon was evil and Saga was good, but Saga went insane for having a Superpowered Evil Side (coms with being the *Gemini* Saint, of all Gold Saints) and turned evil. Kanon *knew* his brother would become evil and used it to his advantage, staging an epic Gambit Roulette that covers several arcs of the story (two in the manga, three in the anime), where Saga was the first Big Bad and Kanon was the Man Behind the Man from both him and his boss. However, later Kanon pulls a Heel-Face Turn and joins the good guys, while Saga turns evil... apparently..
Phenix Ikki (older) and Andromeda Shun (younger) were at first like this. Still, Ikki pulls a Heel-Face Turn early in the story and joins the Five-Man Band.
Apparently Kurumada-sensei loved this trope very much because now in Next Dimension we get the real Abel and Cain, and the Cain once again is the older one.
The most notable case is Sasha and Alone, a brother and a sister who are actually reincarnations of Athena and Hades and are in war against each other for the fate of humans. Sasha is Abel and Alone is Cain.
Tenma and Alone play the childhood friends version of this, with Tenma as the Abel and Alone as the Cain.
As usual, the Gemini Saints end up playing this trope. It's subverted in that, while Defteros was treated badly in the Sanctuary, it was Aspros who became the Evil Twin, due to a growing fear of Defteros' determination to become his brother's equal. He tried to use Defterosas a pawn to kill the Pope (no, not that Pope), and wound up getting killed by Defteros.When he was revived by Alone, he and Defteros had their face-off, and Defteros made a Heroic Sacrifice to restore Aspros' sanity. When Aspros realized whathadhappened...
Teru and Saki were once close while growing up, but an incident during their childhood, the full details of which have not been revealed yet, resulted in their parents separating, each taking custody of one of their daughters, and Teru hating Saki enough to stop talking with her and even deny having a sister. Saki's goal in the series is to face Teru in mahjong and somehow reconcile with her.
In Spiral, Ayumu is struggling with the shadow of his elder brother Kiyotaka, although they don't actually fight until the end of the manga. Also Kanone and the other Blade Children, as they were childhood friends (and, again only in the manga, actually also all half-siblings.
Tekkaman Blade. The English dub (Teknoman) actually names one of the brothers Cain, and Tekkaman Blade II includes the biblical Cain and Abel story in its title crawl. This is also slightly reversed: the elder brother (Takaya/Blade aka Tekkaman Blade) is good, the younger brother (Shinya/Cain aka Evil/Sabre) is evil.
It should also be mentioned that, in the original, The Big Bad, Kengo/Conrad aka Tekkaman Omega, was also Blade and Evil's older brother. And their youngest sister, Miyuki/Shara aka Tekkaman Rapier, is the gentle Sacrificial Lamb who chooses to die through Heroic Sacrifice rather than through her fatal illness.
In Transformers: Robots In Disguise, Optimus Prime's brother Ultra Magnus shows up on Earth with a serious grudge over the Matrix of Leadership having gone to Optimus instead of him, and quite a bit of firepower:
Optimus: He's grown a little bitter over the years.
Side Burn: Bitter? Bitter is not sending you postcards, but this wacko... He knocked you off a cliff!
These two are notably twins with no idea who's older, and the Japanese word they use for their relationship is the incredibly vague 'kyoudai,' but because of the conventions of this trope many fans tend to treat Knives as the elder brother.
Given the vague Christian references that get tossed in, the anime scene that confuses who's supposed to be the Cain here was probably intentional: shortly after Knives kills pretty much everyone else, little Vash stands over him at night with a big rock trying to work up the nerve to bash his sleeping brains out. He doesn't manage it.
Knives, on the other hand, commands 'eternal suffering to Vash the Stampede.' Though he's never quite willing to off him.
Trinity Blood: The battling twins at the center of the story are literally named, "Cain and Abel." Care to guess which of these is the villain and which is the hero? (And to REALLY beat the biblical reference over your head, their little Crusnik "sister" is, of course, named Seth. And their common maternal figure is named Lilith. Right.)
At least somewhat justified, given that the "siblings" were supposed to be the first born (or first created) of a new and improved human species. Initially subverted, as Cain made his first kill in an effort to remove someone he thought was coming between him and Abel. It went over about as well as you'd expect, leading to a more standard example of the trope.
Also subverted in that it was Abel who first went after Cain because of the above murder.
You've got a Big Screwed-Up Family trapped in a mansion possibly murdering each other... Given the context, it would've been astounding if Umineko no Naku Koro nicould have gone without invoking this trope. It's been invoked at a bare minimum, three times.
Folken Lacour de Fanel (Cain) and Van Slanzar de Fanel (Abel) from Vision of Escaflowne, though Folken goes for a Heel-Face Turn mid-series. After all he had done, though, it still takes a lot for Van to forgive him.
This is a slight variation in that there's nothing personal about it from Folken's point of view: they just happened to wind up on different sides of an ideological dispute. It's played straighter in The Movie, which casts Folken as a straight-up Green-Eyed Monster Cain over not being named heir.
Ditto with an older example-Voltes V: Prince Heinel and Kenichi Go. And unlike in most cases of this trope, they have much in common, personality-wise.
X1999: Kamui and Fuuma, in another friendship variety.
The sisters Hinoto and Kanoe count as well. The younger one, Kanoe, is the evil one here though.
In Yu-Gi-Oh! GX, Manjyome hated both his brothers. The originally had a plan to Take Over the World via business, politics, and Duel Monsters, with him providing the last. However, Manjyome really never had any say in the matter. Eventually, he realized he was just a pawn to them, and quit. He got his revenge against them in spades; when they attempted to take over Duel Academy on their own, they demanded a duel from him with him using only monsters that had Attack Points of 500 or less. Manjyome took this one step further, using only monsters with zero Attack Points, and still won, humiliating them beyond belief.
A far worse example in the franchise was Lotten, the main antagonist of the Crashtown arc in Yu-Gi-Oh! 5Ds, who double-crossed his brother Malcolm to take over Crashtown. Of course, Malcolm was a crook himself, but Lotten was likely the only person he trusted. Bad idea; this was truly a case of No Honor Among Thieves.
Zatch Bell: Zatch and Zeno (Gash and Zeon in the original). Zeno hates Zatch because the latter received the powerful "Bao" spells. In the manga, they end up reconciling, but Zeno hates Zatch to the end in the anime.
Aquaman frequently faces off against his evil brother Orm, the Ocean Master.
In the New 52, it's only somewhat of an example. Orm isn't portrayed as outright evil, and the two actually get along pretty well, but once Orm decided to attack the surface, it became this. The reboot also made it a case of We Used to Be Friends, where the two are portrayed as having been very close as teenagers.
Pakrat the thief and his brother Rident Oly the intergalactic police officer in Atari Force.
Batgirl Barbara Gordon and her brother James Jr.: In Black Mirror, James attempted to murder Barbara by driving knives into the arteries in her legs and then pulling one out himself. He also set his sister up in Death Of The Family.
Since his resurrection, Jason Todd has repeatedly attacked his adoptive brothers Dick Grayson and Tim Drake. It came to the point that in Battle for the Cowl he actually tried to kill them.
Damian also has this toward Tim, reasoning that he would have to kill the then-current Robin to get Batman's respect. He's undergone some Character Development since then, but there still isn't much brotherly love between him and Tim.
And in the New 52, Owlman is (supposedly) Thomas Wayne Jr., Bruce's brother.
In one story in the Batman Black and White motion comics, one of Harvey Dent's many, many attempts to become sane again is ruined because his plastic surgeon fiance had a psychotic twin sister who was even crazier than Two-Face.
Rose and her sister, from the epic adventure Bone by Jeff Smith.
Kalibak, son of Darkseid, is the adopted brother of Mister Miracle, the biological brother of Orion, and an enemy to them both.
Hawkeye and his older brother Trickshot. Trickshot even impersonated his brother during his time with the Dark Avengers, just to piss him off.
Skaar and Hiro Kala, the twin sons of The Hulk. Hiro-Kala wanted to kill Skaar, and then himself, to finally destroy the Old Power they inherited from their mother, as he believed it would eventually destroy the universe. Main problem was that he was going to do this by crashing a Mars-size planet into Earth to destroy both worlds, in his words "sacrificing billions to save trillions."
The Marvel versions of Hercules and Ares are bitter rivals throughout their comics histories. In The Incredible Hercules, Ares' primary reason for despising Hercules is said to be his anger that mortals favoured Hercules over him, despite all the benefits (fame, power, empire) that war brings. But he overlooks the bad things of war (death, destruction, fear and often a heavy poverty)
Black Bolt, leader of The Inhumans, and his brother Maximus "the Mad".
Judge Dredd and his brother, Rico. Dredd arrests Rico after he goes rogue. Twenty years later, Rico comes back for revenge and Dredd is forced to kill him.
Luke Cage and his brother Coldfire. Iron Fist has the friendship version of this with Davos/Steel Serpent.
J'onn J'onnz, the Martian Manhunter, also had his share of troubles with his evil sibling Malefic, who was responsible for wiping out the entirety of their species, before J'onn tossed him into the sun.
Though it's never established if they're blood siblings or not, John Doe and Alfie O'Meagan from Nth Man: The Ultimate Ninja are same-age infants who were found and raised in the same orphanage. The series centers around John's efforts to stop Alfie from destroying the world.
The Sandman and associated titles feature Dreaming versions of the original Cain and Abel. Abel is harmless, but Cain feels driven to repeatedly murder him. Furthermore, Cain won't stand for anyone else harming Abel. These versions of the characters are originally from DC's 70s horror titles.
In a less literal example, Desire has sworn to set the Kindly Ones on his/her brother Dream. In this case, Desire is the younger sibling.
In the Sonic the Hedgehog comics, Lien-Da and her brother Kragok hated their half-sister Julie-Su due to their belief that their father liked herbetter. Kragok's dead these days, but the rivalry between Lien-Da and Julie-Su is still going strong - and it's not helped any by Lien-Da working for Eggman and Julie-Su being Knuckles' girlfriend.
Lien-Da's actually been on both sides of this - she and Kragok were supposed to take over the Dark Legion together after killingtheir father, but Kragok set things up so that Lien-Da would be badly injured in the process, so he could cheat her out of the position.
In a more metaphorical sense, there's Shard (the original and reformed Mecha Sonic rebuilt by the Secret Freedom Fighters) and the current Metal Sonic (still loyal to Eggman), who view each other as brothers, with Metal dedicated to destroying Shard.
During a brief Dork Age, that was thankfully swept away by Infinite Crisis, Supergirl's father Zor-El hated his brother Jor, and sent Kara to Earth to kill Jor-El's infant son. Or he just didn't get on with his brother, and knew that Kal-El would "infect" Earth with evil spirits from the Phantom Zone. Or... look never mind, it's gone!
In Superman & Batman: Generations, Joel Kent, who was prenatally stripped of his Kryptonian superpowers by Gold Kryptonite exposure, was the Cain to his sister Kara's Abel, and in the same Biblical fashion ended up killing her when he got superpowers.
Anyone who's a fan of the Teen Titans cartoon knows that Starfire and her sister Blackfire are enemies... Their hatred for each other is a lot worse in the comics.
Starfox and Thanos the Mad Titan. Their father forced them to agree to meet once every thousand years on peaceful terms in the hopes that they would eventually stop fighting altogether. So far they haven't.
Although they're both heroes, Cyclops and Havok frequently find themselves fighting against each other.
In fact, it happens so often, fans sometimes forget that Cyclops and Havok are quite close in 616 continuity (that is, whenever Cyclops isn't being a Jerk Ass and Havok isn't plagued by the Green-Eyed Monster or Brainwashed and Crazy). On the other hand, they unabashedly despise one another in Ultimate and Misfits continuity, making this trope much more applicable to those universes.
Played straight between Cyclops and his other brother Vulcan.
Played even more straight between Havok and Vulcan after the latter killed their father.
Wolverine and Sabretooth aren't brothers per se, but they were both products of the Weapon X project, and at one point it was (wrongly) believed Sabretooth was Wolverine's father.
Though Chris Claremont has suggested that Sabertooth being Wolverine's father was the original plan.
And in the first arc of Joe Quesada's Origin, Wolverine's half-brother Dog was strongly implied to be a young Sabretooth, but later stories disprove this. However, Dog and Wolverine still have an antagonistic relationship, so they fit here.
The film versions of them are explicitly stated to be brothers.
Emma Frost and her sisters, especially Adrienne whom she shot to death after Adrienne's actions led to Synch's death.
There's also the human Graydon Creed and his mutant half-brother Kurt Wagner/Nightcrawler.
Now Daken and X-23 can be added to the list, being the son and daughter of Wolverine. Daken is what Wolverine is trying to make sure X-23 does NOT end up like.
Though if you want to get technical, since X-23 is a female clone of Wolverine, she is actually more like Daken's aunt.
Colossus and his (now currently deceased) brother Mikhael Rasputin. His relationship with his little sister Ilyana is only slightly better: Colossus is fiercely protective of her to the near detriment of every other aspect of his life, but she's a soulless demonic being (who nonetheless still loves Colossus as much as a soulless demonic being is capable of love). Eventually Ilyana forced Colossus to understand that she isn't the same innocent little sister he loved by manipulating him into suffering demonic possession as the new Juggernaut. When Colossus learned the truth, as well as the fact that Ilyana could have freed him at any time, he vows to kill her if they ever meet again. Ilyana is disturbingly pleased by this.
In "Fair, Brown, and Trembling", the two older sisters refuse to let their sister out of the house for fear she would marry before them. When she succeeds in marrying anyway, her oldest sister pushes her into the sea and takes her place.
In "Finette Cendron", Finette's sisters force her to stay home from the ball.
In "The Grateful Beasts", Ferko's brothers put out his eyes and break his legs. Then they slander him to the king to persuade him to set Ferko to Impossible Tasks until, finally, Ferko has wolves eat the king, his own brothers, and all the court.
In "The Singing Bone", the younger brother is murdered by the envious older. His corpse rots, someone retrieves a bone from it and makes a flute, and the flute begins to sing of the murder. (Gustav Mahler adapted this tale for his early work Das klagende Lied.)
The same sort of thing happens in a large percentage of Russian fairy tales. Either there will be three brothers or three sisters. If there are three brothers, then the two oldest will be greedy and ambitious, and the youngest will be lazy, considered a fool, and usually named Ivan. The youngest brother will compete with his older brothers for something, and will always win through kindness and wisdom. If there are three sisters, the oldest two will be lazy, greedy, and vain, and the youngest will be the only one who ever does any work. The youngest will always get to marry the prince.
Kristoph and Klavier Gavin in Dirty Sympathy. While they have not hurt each other directly, there's a reason that Klavier is willing to frame his brother and he tells Apollo outright that he would have been in Apollo's position if he hadn't left.
Graduate Meeting Of Mutual Killing has brothers Reiji and Yukio Ohmoto. The former was the Assistant, while the latter was the Master. After a blunder Yukio did was quickly (and unsuccessfully) concealed via Twin Switch, Reiji got a spot in the Administrative Council of Hope's Peak. The influence and position of that spot gave Reiji what he needed to usurp Yukio's title and past, ending with Reiji as the Master and Yukio as the Asisstant.
Bataar and Unegan in Hachin. Notably, it's actually the younger brother who's the Cain is this case.
Inner Demons: Sweetie Belle and ScootaloojoinQueen!Twilight, turning on Rarity and Rainbow Dash, their respective sister and sister-figure. And of course, Queen!Twilight herself ends up in this relationship with Shining Armor (though that's not her original plan). In all three cases, it's the younger one who's evil.
In the Shining Armor Arc, it eventually turns out that Makarov and Dima are half-brothers, with the former being the Cain.
The former is also the Cain in a more symbolic relationship: when he starts warping reality to wipe out his enemies and make himself the grand hero of the world, he kills all the Changelings, including Chrysalis; both Makarov and Chrysalis were created by Pandora, making them siblings of sorts. Of course in this case Chrysalis is just as much of monster as her "brother".
On that note, it's revealed that Chrysalis was created from the Shadow of Existence of the original Cadenza, while Cadence was made from her Light. This makes them "twin sisters", as Chrysalis puts it, making her the Cain to Cadence's Abel.
Mufasa and Scar in The Lion King, with the unfortunate addendum that Mufasa had no idea Scar was plotting against him until it was too late. A rare case where the younger brother is the evil one.
In an interesting if debated adaptation choice, the film The Prince of Egypt made Moses the adopted brother of Rameses instead of his nephew, then played this trope to the hilt.
The Biblical version had Moses found by Pharaoh's daughter, while The Prince of Egypt had his foster mother as Pharaoh's wife. Given marriage customs among Egyptian royalty of the time period, the same woman could easily be the daughter of Pharaoh X and the wife of his successor, Pharaoh Y. Thus, identifying her by her relationship to a Pharaoh depends on which Pharaoh is the point of reference.
The vicious Red Queen in Tim Burton's Alice in Wonderland jealously loathes her younger sister, the benevolent White Queen, because the latter is adored by the populace (and, to judge by a throwaway line toward the end of the film, was the favorite of their parents).
Lucas Strong and Kid Shaleen in the musical western Cat Ballou.
In The Challenge, Toshiro Mifune plays a modern samurai master fighting his evil younger brother over ownership of "The Equals", a pair of sacred katana swords.
In the backstory of The Curse of the Mummy's Tomb, Ra-Antef, the Mummy of the film, was a noble man who sought knowledge as the forthcoming Pharaoh and his brother Re was a scheming hedonist who was so jealous for his older brother's success that he organized him to be banished and later assassinated.
Dead in Tombstone: Red and Guerrero are half-brothers. Red has always been jealous of Guerrero, despite the fact that Guerrero has always looked out for him. Red talks the rest of gang into betraying Guerrero and fires the first shot in the fusillade that kills him.
In Desperado, when the Mariachi and Bucho finally face off, it turns out that they are both brothers. The Mariachi is Cesar's Manito (little brother in Spanish), while his brother is Cesar.
In fact, Desperado has a story very similar to Il Trouvatore, where the same thing happens.
Adam (Cain) and Fenton (Abel) Meiks in Frailty. Adam dutifully followed their deranged father's religious beliefs that he and his sons were hunting down demons on God's orders while they were actually murdering innocent people; Fenton always feared him and knew what they were doing was wrong. After they both left the home, Fenton has been hunting down his brother, who continued to be a serial killer. And then the twist comes...
In Gattaca, the main character Vincent was conceived without any of the advanced genetic screening that his younger brother Anton receives, and is thus subject to nearsightedness and a high likelihood of developing a heart condition. Their father clearly favors Anton throughout childhood (deciding at the last minute to not name the first-born son after himself when the potential heart condition is discovered at birth, saving that for his perfectly engineered second son). This favoritism coupled with the societal discrimination against naturally conceived "faithbirths" causes Vincent to hide his identity in order to pursue his dream of becoming an astronaut.Later, the police detective who discovers Vincent's deception is revealed to be Anton, who feels insecure about how successful Vincent is despite his 'inferior' genetics (due to his determination).
In The Godfather Part II, Michael Corleone has his brother Fredo assassinated.
In another MCU film, Guardians of the Galaxy, Gamora and Nebula have a relationship very similar to Thor and Loki's. Including being adopted siblings, the Cain having resentment issues because the Abel is the favorite of a father figure and of course Cain and Abel having very tangled love/hate relation.
The two pharaohs in Night at the Museum - Battle Of The Smithsonian: The elder (Hank Azaria) was utterly ruthless while the younger one was wise, and for that, "mother and father" gave Egypt to the younger one.
With the release of Prometheus, the relationship between the Humans and the Xenomorphs became something of this trope, as it was revealed that both species were created by ancient, humanoid creatures nicknamed Engineers, or Space Jockeys, in their bioengineering experiments. However, this trope is reinforced as the Engineers created the Xenomorphs in order to wipe out their former creation, the Humans, for reason unknown, and even when it looks like the last Engineer died by the end of Prometheus, the deadly hatred the Humans and the Xenomorphs have to each other still remain active even centuries afterward.
In The Proposition, Charlie Burns is blackmailed into killing his evil older brother Arthur, using Mikey, the younger, "simple" brother, as leverage. Ironically, their names starts with the initial, C and A. Though Charlie is the Abel and Arthur is the Cain. He eventually does, but by now Mikey's already dead, and it's just because Arthur deserves to die.
Luigi and Pavi Largo in Repo! The Genetic Opera. In this case, the hatred is definitely mutual. The existence of sister Amber is a slight complication, though... they don't dare actually try to kill each other for fear fabulously wealthy daddy Rotti will disinherit both of them.
In Stahlnetz: PSI two brothers kidnap a little girl for ransom. When the elder brother, having a family of his own, gets second thoughts about the whole thing, the younger brother beats him up, locks him with the girl and abandons both to die. They are rescued by the police shortly thereafter.
In Star Wars Episode III: Revenge of the Sith, the battle between Obi-Wan Kenobi and Anakin Skywalker is punctuated by Obi-Wan calling Anakin his brother.
Transformers: At the climax of the 2007 film, Optimus calls Megatron "brother". Peter Cullen, who voices Optimus, publicly referenced the story of Cain and Abel when describing the revelation.
How that works with giant robots was unexplained.
More explicitly in the sequel, the Fallen is revealed to be one of the Prime family, the original leaders of the Transformers. Optimus is either his brother or his nephew.
The Kaiju film War Of The Gargantuas has Sanda and Gaira, Bigfoot-like creatures grown from remains of a giant Frankenstein's Monster, that battle to the death as a result of Sanda's opposition to Gaira's Kill All Humans attitude.
The first half of The Wind That Shakes the Barley is the O'Donnell brothers (Cillian Murphy and Padraic Delaney) fighting in the Irish Revolution together, and making enormous sacrifices. The second half is them choosing different sides in the Irish Civil War, and making even bigger ones.
In Year One, Cain and Abel are encountered early on by the main characters, who very nervously befriend Cain after the infamous act (which he violently denies) and ends up selling them into slavery. Later on, they meet Cain as a town guard of Sodom and he sells them out to the king to be sacrificed.
Gladiator: Commodus as the Cain, Maximus as the Abel. They're not related by blood, but Marcus Aurelius considered Maximus the son he should have had instead of the ambitious Commodus and nominates him as regent. Commodus also considers Maximus his non-blood brother, as both try to win Aurelius' favor and Lucilla's love. However, Commodus resorts to murdering his father and arranging to rape his sister, while setting up Maximus' death several times. Discussed near the end:
Commodus: That makes us brothers, doesn't it? Then smile for me, brother! [stabs Maximus throught the chest]
Lockout: The two brother convicts Alex (Abel) and Hydell (Cain). Both are criminals, but Hydell consistently screws up his brother's attempts at Pragmatic Villainy by killing as much as he wants once the prisoners are in charge, even when it hurts their plans. Hydell eventually murders Alex, thereby dooming himself.
Lucasfilm's Alien Chronicles had a pair of childhood friends in a pet or slave/master relationship that later grew into a deeper friendship. One grew up to be Empress of The Empire, while the other became the leader of La Résistance.
Ser Gregor Clegane badly burned half his younger brother Sandor's face as punishment for playing with his toys when they were children (worth noting Gregor was 11, already the size of a man, and a squire with no interest in the toy in question, while Sandor was only 6 and probably half Gregor's size), and Sandor now lives only for revenge on him.
Lord Stannis Baratheon and Lord Renly Baratheon, but it's difficult to determine which of them is the bad guy there. Stannis is over a decade older and is the rightful heir to their older brother's throne, but Renly attempts to usurp his place. However since Stannis is the one who had a sorceress assassinate his brother, he looks like the bad guy.
It's worth noting that, in the television series adaptation Game of Thrones, Renly didn't want the throne at first and was persuaded to make his bid for kingship by the Tyrells, partly because no one in the Seven Kingdoms wants Stannis for their king.
Queen Cersei Lannister lives in fear of a prophecy predicting she will be strangled by her younger brother, an act Tyrion certainly has plenty of motivation for. Things started looking really bad for Cersei when Tyrion Took a Level in Badass and escaped from death row, strangling his treacherous ex-lover and fatally shooting his father on his way out, as well as planting the seeds of resentment in his brother Jaime. However, as Ser Jaime, Cersei's twin and incestuous lover, was born moments after she was, he could also turn out to fulfill this prophecy.
Domeric Bolton & his bastard half-brother Ramsay Snow. Domeric seeks Ramsay out in hopes of befriending him; Ramsay poisons Domeric for his trouble.
Catelyn Stark and Lysa Arryn. But although Catelyn sees that Lysa is unstable when she visits the Eyrie, she has no idea that Lysa both truly hates her and is party to Littlefinger's plots, which lead to Catelyn's death.
In The Hedge Knight the Prequel novella, Egg hates his elder brother Prince Aerion Brightflame, passionately, and openly roots for challengers to kick his ass. A more tragic example is that between his father, Prince Maekar and Prince Baelor Breakspear. Maekar resented his brother who was more likable and good looking than him, and hated the fact that his children would inherit before Maekar's. But even then he never wanted to kill him. In the Trial by Seven, Maekar and Baelor tussled and a poorly timed hit from Maekar's mace damages his brother's brains and kills him.
The Bible itself, of course, but in addition to the Trope Namer there was also Esau and Jacob (this didn't come down to actual murder, though at one point Jacob was afraid it would (justifiably, given that he'd screwed Esau out of his inheritance)) and Pretty Much All Joseph's Brothers and Joseph (again, stopping just short of actual murder... they only sold him into slavery and told everyone he was dead).
Thomas and Christian in Buddenbrooks. Thomas is the strict businessman (although sometimes, it becomes too much for him), Christian a playboy and a neurotic. At one point, Thomas threatens Christian to put him under tutelage. Thomas also tells him, "I became what I am because I didn't want to become like you!"
Bekter and Temujin in Wolf of the Plains, brought to a head when Bekter steals a marmot Temujin had caught and passes it off as his own kill. Temujin and Kachiun kill him soon after.
Raistlin and Caramon Majere, fraternal twin-brothers from the Dragonlance fantasy novels by Margaret Weis and Tracy Hickman. (Dragonlance is also one of the older Dungeons & Dragons world settings). Raistlin, the smart but sickly ambitious one, grew up to be a wizard (something he had considerable talent for), while the warrior Caramon was big, muscular and good-natured but somewhat dense.
Actually, they're an aversion of this trope. Although they're very different, and Genre Savvy fantasy fans would expect them to be enemies (of the Black Magic vs Knight Templar variety), they're actually quite close. Caramon is fiercely protective of Raistlin despite seeing Raistlin kill a simulacrum of Camaron during his magical testing out of jealousy.
Not really, Raistlin has on several occasions shown himself to be entirely capable, and willing, of killing his brother, who he is intensely jealous of. Basically the only thing stopping him from killing Caramon is that he needs Caramon's strength to protect himself when he's used up his spells for the day. Raistlin also repeatedly states, and demonstrates, that if killing Caramon would guarantee unlimited power for himself, he would do so.
Let's just say that Raistlin first, and Caramon later go through a big phase of Character Development. So, at the start this trope is averted, and at the end it's played straight. And then it's subverted.
John Steinbeck's East of Edenpractically plagiarizes the Book of Genesis in its portrayal of two generations of brothers in the Salinas Valley of California. The story of the first pair of brothers, Adam and Charles Trask, follows the Biblical story of Cain and Abel very closely, and it is mirrored by the relationship of Adam Trask's two sons, Aron and Caleb. Excellent book. Made into a 1955 film starring James Dean.
Ender’s Game does this in spades with the titular character and his older brother Peter. They don't reconcile until the Abel is half a galaxy away and the Cain is on his deathbed.
Also notable because Peter united the Earth and the Human Race while Ender obliterated an entire race of sentient beings. Well, almost an entire race.
In the Chivalric RomanceGamelyn, the plot revolves about how Gamelyn is oppressed by his older brother while his ward. He takes his Revenge and hides as an outlaw in the woods until he wins the king's pardon. (A source for As You Like It and Robin Hood ballads both)
Sam and Caine in the Gone series. In a slight variation, Sam (the good one) is older by a few minutes (they are twins Separated at Birth), and neither has killed the other yet, although they are enemies.
In Gone with the Wind, Scarlett and Suellen qualify. Scarlett dislikes Suellen, seeing her as whiny and constantly complaining. Scarlett later marries Suellen's fiance from right under Suellen's nose.
Gravitys Rainbow: Russian mercenary Tchitcherine spends the novel trying to hunt down and kill his black half-brother.
Sadaiyo (Cain) and Ashinji (Abel) of Griffin's Daughter: Ashinji was kind, humble and beloved by all. Sadaiyo was a sociopathic sadist who blamed his brother for the fact that everyone hates him, especially their father, Lord Sen (or so Sadaiyo believed). Sadaiyo ends up setting Ashinji to be taken prisoner by a human raiding party. When Ashinji returns a book later, Sadaiyo snaps and tries to kill him on the spot.
And then there's Galaxy in Flames, Flight of the Eisenstein, and Fulgrim, which are absolutely rife with this; each Legion is a brotherhood, and no less than four of them - the World Eaters, Sons of Horus, Death Guard and Emperor's Children - are ripped in half by Horus' ambition, leading directly to brother vs. brother combat on a gargantuan scale.
It looks very much like this is going to happen with Remiel and Zahariel in the Dark Angels books in the series. Ultimately averted: Remiel has already been killed.
Also looks to be the case with Alpharius and Omegon.
Fulgrim is a magnet for these: after developing and concluding a feud with Ferrus Manus, Primarch of the Iron Hands, by killing him in Fulgrim, he then hatched a plan to sacrifice his fellow traitor Primarch Perturabo in order to earn daemonhood in Angel Exterminatuswhich failed, but Perturabo is pissed, and canon indicates that eventually he's going to stab a third Primarch, Roboute Guilliman of the Ultramarines, with a poisoned blade and necessitate that he be sealed in stasis.
Kyle and Ian from The Hostjust skirt being this. Jeb and Maggie also come close, in a rare brother-sister variation of the trope.
In Julie Kagawa's The Iron Daughter, Rowan fights Ash as he tries to rescue Meghan from the court. Later, they learn that Rowan let the Iron Fey into the court, where they killed the oldest brother, Sage.
In Ishmael, the Taker and Leaver cultures are described as being the inspiration for the original story.
In the final book of the Star Wars: Legacy of the Force series, twins Jaina Solo (Sword of the Jedi) and Jacen Solo (Darth Caedus) fight two brutal lightsaber duels. At the end of the second duel, Jaina kills Jacen. In contrast to the Cain and Abel original archetype, it is the one doing the killing who is the protagonist and the slain who is the villain...even though it was the antagonist Jacen who tried to get out of the fight to save his loved ones but was denied any escape or surrender by his sister, supposedly the heroine of the series.
Little known fact: You lose your right to Time-Outs when you kill your aunt in order to turn the galaxy into a Police State.
The point was that the twins weren't as far apart morally as they (or just Jaina) might have thought. At any rate, Vader was worse than Caedus, and yet he was given the chance to be redeemed at the end.
Jaina realizes this after she kills him. Hence her breakdown where she throws Jagged Fel away from her with the Force when he tries to move Jacen's body. (Plus, Jaina thought that the "I want to save my loved ones" thing was a trick. She didn't have much reason to believe that he wasn't trying to trick her, what with him kidnapping his daughter and all.)
It turns out that they were right about Jaina and Jacen, but about a decade early.
Eve and Alexandra Blackwell in Sidney Sheldon's Master of the Game are twins born into one of the most powerful business dynasties in the world; Eve arrived first, and her ambition makes her the obvious one to take it over once matriarch Kate retires...but Eve is insanely resentful of Alexandra simply because she keeps people from devoting themselves to Eve entirely. The night before their fifth birthday, Eve tries to kill her, and from there she devotes her life not only to becoming the inheritor of Kruger-Brent, Ltd., but crushing Alexandra as well.
In Memory, Sorrow, and Thorn, royal half-brothers Elias and Josua are this to a tee. Elias, older and more martial, hates his brother with a passion and considers him a rival for power. Josua, younger and more studious, repeatedly disclaims any desire for the throne and views his brother with a kind of pity, understanding that Elias' hatred stems from love of his wife, whose death he blames on Josua. Their falling out is heightened by Elias' recruitment of Evil Sorcerer Pryrates as a trusted advisor, which Josua repeatedly advises his brother against. The feud escalates to the point that Elias, at Pryrates' behest, has Josua captured and imprisoned, intending to use him as a ritual sacrifice to seal his deal with theStorm King, making the Biblical allegory even more blatant. Ironically, it turns out that Josua and Elias aren't blood relatives at all, as Josua was sired not by the king but by his most loyal knight, in a betrayal that has profound consequences on the story.
The Mythos has this relationship between Cthulhu and his "half-brother" Hastur. In fact, it's because of this rivalry that The Unspeakable aids Laban Shrewsbury's fight against Cthulhu, despite being a Great Old One himself.
Robin Hobb's The Farseer Trilogy has Regal, the younger half-brother of Chivalry and Verity, and last in line for the throne. After Chivalry abdicates, this puts Verity into a dangerous position, and later his pregnant wife, as well, not to mention the protagonist, Chivalry's illegitimate son.
In Septimus Heap: Flyte, Simon Heap is hunting down his younger brother Septimus and trying to eliminate him, to get the ExtraOrdinary Apprenticeship.
In Neil Gaiman's Stardust, the customary method of royal succession is that the last prince to survive Free For All fratricide among his brothers becomes the heir.
In the "I.K.S. Gorkon" Star Trek novels, Klag and Dorrek have this kind of relationship, stemming from some complicated business involving their father. At the end of the second book, Klag - as Head of House - disinherits Dorrek in a variation on I Have No Son, and it ends up being the Klingon governing council who end up killing Dorrek, instead of Klag.
Trapped on Draconica: At the start of the story, Daniar and Rana are not on speaking terms; Daniar and Zarracka are full-on enemies. In both cases, Daniar is the Able.
In Graham McNeill's Warhammer 40,000Ultramarines novel Nightbringer, Barzano is warned as soon as he arrives on planet that Talhoun is suspected of having murdered his brother in order to become the family patriarch.
In The Vampire Diaries, the Salvatore brothers, Damon (Cain) and Stefan (Abel). Damon, the Cain, has always loathed his younger brother, Stefan, the Abel. Most of it has to do with jealousy and competition between the two brothers. Also, their personalities fit the Cain and Abel trope. Damon (the Cain) is selfish, jealous, impulsive, dangerous and violent, and Stefan (the Abel) is kind, compassionate, empathetic, selfless and pure of heart.
The first two arcs of Warrior Cats end with a character killing their brother. Specifically, Firestar kills Scourge (but Scourge killed Firestar) and Brambleclaw kills Hawkfrost.
Also, in Omen of the Stars, Ivypaw gets jealous of the attention Dovepaw is getting and is tricked into joining forces with the Dark Forest. This was averted later though.
In Terry Pratchett's Witches Abroad, Granny Weatherwax reveals a deep-set resentment of her older sister - not because she's evil, but because her choice forced Granny to be the good one. Lily, a Knight Templar who believes she's the fairy godmother battling the wicked witch, is totally shocked at this interpretation.
In William King's Warhammer 40,000Space Wolf novel Wolfblade, Ragnar is warned that the brother of one House's lord died very suddenly and suspiciously.
By the Light of the Moon: the protagonists encounter Kenny of the many knives, and fear he will do a bad thing involving his knife collection and his younger brother Travis.
The Vision: two brothers-in-law (her elder brother and her husband, respectively) are rivals for Mary's attention; her husband as of the beginning of the story has supplanted her brother and taken over the management of her business affairs.
Watchers: Einstein and the Outsider are considered the two children of the Francis Project - one beloved, the other hated and feared (and aware of both facts, which is why the Outsider seeks to kill Einstein).
The Bad Place: Frank (older, co-protagonist) wants a much more normal life than his mother's mental problems and the odd abilities in the family really allow, while psychopathic brother "Candy" (real name James) is determined to kill Frank for killing their mother.
All evil is brought into the world by Melkor-Morgoth, one of the Valar, very powerful angel-like beings Eru created to prepare Arda (Earth) for Elves and Men. Since Morgoth interferes with Eru's plans and destroys or ruins everything the other Valar help create, his "brother" Manwë is appointed king of Arda because of his faithfulness to Eru.
Fëanor and his younger half-brother Fingolfin, high-elven princes: Fëanor resents his father's remarriage and dislikes his father's second wife and children even before they're born (even though his father still favoured Fëanor.) Morgoth spreads lies to worsen things, until Fëanor raises a sword against Fingolfin in cold blood. Although Fingolfin immediately forgives him and tries to reconcile, Fëanor eventually abandons his brother and nephews/nieces, leaving them either to go beg the Valar for mercy after having committed some fairly questionable acts, or to migrate on foot across a deadly strait filled with shifting sea-ice.
In Animorphs main hero and team leader Jake's older brother Tom is a Controller, a host for an alien parasite who would infest him as soon as look at him. Slightly subverted in that the real Tom is not Jake's enemy and just a helpless slave of the Yeerk in his head
In Battlestar Galactica (Reimagined), any serious conflict between the Cylons amounts to this, since all but the five originators of the race are brothers and sisters by relation.
John murdered his brother Daniel out of jealously because his mother loved him more, polluting the models during their assembly process. He later kills half his siblings for rebelling against him.
Boomer and Athena's interaction also becomes increasingly hostile as Boomer feels that Athena got the life she should have had. Athena knowingly started out as a Cylon before joining the humans willingly, while Boomer believed herself to be human before having her Cylon nature forced upon her. She threatens to kill Athena's daughter Hera before Six kills her. After downloading again Boomer later beats up Athena and ties her up, then forces her to watch as she makes out with Athena's human husband Helo and kidnaps her daughter for Cavil.
In Beetleborgs, at the start of the Metallix season, the kids contact Arthur "Art" Fortune, the Stan Lee-like creator of the comic book, to revamp their superhero alter-egos. Meanwhile, the villains hook up with Lester "Les" Fortune, his jealous and psychotic brother who is serving a prison sentence, to draw new minions for them. Working for opposite sides only propels the brothers' long-time hatred for each other.
Tommy and Michael Caffee in Brotherhood. Tommy is a up-and-coming state politician with a young family; Michael is a senior figure in The Irish Mob with a Hair-Trigger Temper. As the series progresses, it turns out they're Not So Different morality-wise, but they remain at odds with each other.
Buffy the Vampire Slayer: Caleb, The Dragon to the final Big Bad, identifies Faith as 'the Cain to Buffy's Abel' in his first appearance. Faith later concedes that jealousy over not being the Chosen One probably contributes to her tendency to be at Buffy's throat and to her going rogue in earlier seasons.
An episode of Cheers ("Ma Always Liked You Best") involved Woody bonding with Cliff's mother and Cliff becoming jealous, leading Mrs. Clavin to say she wanted to avoid "a Cain and Abel situation" and agreeing that they may "share" her.
Horatio and Raymond Caine in CSI: Miami. Horatio and Ray are portrayed in direct contrast to one another, with Horatio portrayed as a Good Cop to Raymond's Dirty Cop. Some episodes in the earlier seasons of the show had Horatio dealing with indiscretions Ray (who was believed to have been murdered while undercover but was actually Faking the Dead the whole time) had committed while undercover, including fathering a child with another woman, getting involved with criminal gangs and drug addiction. It was also implied that Horatio had feelings for Ray's wife Yelina, a Story Arc that never got resolved after Ray came out of hiding to reunite with Yelina and their son (but later got Killed Off for Real anyway, dying in Horatio's arms).
J.R. and Bobby Ewing from Dallas are a perfect example, with J.R. as Cain and Bobby as Abel. Though Bobby was the one that once tried to drown J.R. in Southfork's swimming pool.
In Deadwood, Francis Wolcott is buying up all the goldmines around town for Hearst. In the case of one mine owned by two feuding brothers, he manipulates one brother to murder the other in order to get the sale.
Dexter Season 1 focused on Dexter and Brian/The Ice Truck Killer, who was Dexter's biological brother. He served partly as an example of what Dexter would be without the Code of Harry and cleared up heaps of backstory. In a twist on the usual story Dexter killed Brian. I'm not sure which one was Cain and which was Abel...
Subverted: even when siblings and death occur, it's not about sibling rivalry per se.
The Doctor and The Master in Doctor Who. It's never been confirmed on the show that the two are actual brothers, and the Doctor denies in the revived series - although the Doctor isn't the most reliable source when it comes to his past. Even if they're not biologically related, the series makes it clear that they were as close as brothers growing up, so it still counts.
Sean and Eric Renard of Grimm. At this point, it looks like Eric is Cain to his half-brother's Abel, but it can be hard to say with these two. Their problems include serious philosophical differences about how the Wesen world should work, probable rivalry for power (Eric would seem to have the edge, being the legitimate royal, while Sean is the product of an extra-marital affair on their father's part), and the question of which one is the father of Adalind's child. Granted, neither knows about this last problem yet, but it's just waiting to be used against both of them.
In an interesting variation, Nathan and Peter Petrelli from Heroes spend the entire first season being set up as this—with Nathan, the older one, being loyal to their crazy Utopia Justifies the Means mother and a bit of a jerk to boot, and Peter, the younger one, representing all that is good and pure and idealistic—but the climax of the first season finale has Nathan ultimately rejecting his mother's side and dramatically sacrificing himself to help Peter save the world. Even if he didn't actually die. Of course, many of the fans believed something like that would happen all along, and were made very happy by the mutual declarations of love that came with it...
After the events of Volume 3's finale, it looks like Peter and Nathan are heading into this direction after all.
This was sometimes the case in I Dream of Jeannie. Jeannie's sister (also named Jeannie, also played by Barbera Eden, but with a brunette wig) was clearly evil and often tried to steal Tony for herself, but whether the two sisters were enemies depended on the situation. (Sometimes Jeannie was naive enough to trust her, but not always.)
KITT and KARR from Knight Rider could arguably be considered an A.I. version of this, with older prototype KARR the Cain to KITT's Abel.
Kyoryu Sentai Zyuranger has Burai's opposition to his brother Geki as much of the focus of the story- eventually however, the two are reconciled and Burai becomes the original Sixth Ranger.
In LOST, it has been revealed that Jacob and the Man in Black are brothers.
Bud and Kelly Bundy on Married... with Children are a very strange case. Very often, they are like this, willing to turn on each other and double cross each other, even breaking out into actual fist-fights at times. On the other hand, there have been times when the two have stuck up for one another, and one has defended the other sibling from another tormenor. Kelly has even gone out of her way to dole out punishments on girls who play cruel tricks on Bud. It's likely a case where it is Depending on the Writer, but it's a Big Screwed-Up Family in every sense of the term.
Arthur and Morgana on Merlin. Arthur is the Abel (the Big Good) to Morgana's Cain (the Big Bad). Morgana spends most of her time plotting to bring Arthur down and has made many attempts to kill him and make him suffer. And it seems as though she doesn't even care even after learning that he's her half brother. It's a far fall from when she actively defended him in 1x07.
In the Monk episode "Mr. Monk's Other Brother," Monk ends up taking in his half-brother, prison escapee Jack Monk, Jr. When Adrian is in session with Dr. Bell and explains his conflicts he's dealing with (he knows Jack is a fugitive, but at the same time, there are moments that he isn't unbearable to live with), Dr. Bell makes note of the Cain and Abel analogy to explain Adrian's feelings.
One episode of MythQuest retells the story of Osiris and his brother Set. Set is jealous of Osiris' fame, wealth, and power, so he devises a plan to poison Osiris and take his place. When Alex, an Intrepid Fictioneer who is taking the place of Osiris, learns of this, he calls Set "the worst brother since Cain."
Dan and Keith from One Tree Hill always had a rivalry because of Keith's love from Dan's ex, Karen. In season 3, Dan kills Keith because he believed Keith tried to kill him in the previous season; actually it was his then-wife, Deb. Abby who witnessed the murder left taunting messages to Dan which quoted the Cain and Abel story.
And it comes up again in Power Rangers Operation Overdrive, this time between villains. The season has multiple Big Bads competing with each other as well as the Rangers, and the two most prominent are brothers Moltor and Flurious.
In season 7 of Smallville, Lex Luthor ends up creating his own Cain and Abel, when it's revealed he made Grant Gabriel as a clone of his dead baby brother. When Grant discovers this, he becomes very angry and hateful of Lex. Grant tries to form a familial relationship with their father Lionel against Lex's wishes. So Lex hires a hitman to gun him down. Then Lex goes outside to scream in the rain.
Smallville also has a version of Zor-El, Supergirl's father, who is antagonistic towards his brother Jor-El because of his love for Jor-El's wife, Lara.
Lex and Clark Kent have been billed as being in a Cain and Abel relationship since the very first episode it seems.
And in Earth-2, Clark was adopted by Lionel Luthor. Didn't end well for Lex. And father is OK with that because he believes in social darwinism. However, Lionel was furious that his adoptive son hasn't killed him yet, as should be expected. After coming to "our" universe, he's soon began to miss his son and planned to revive "our" Lex. Which he did.
Jor-El and Zod were also similar to Clark and Lex.
Lex ultimately ends up the Cain to yet another sibling- younger half-sister TessMercer, who he murders in the Grand Finale. His reasoning is that it's a version of a Mercy Kill so that she doesn't end up likehim, but few people buy that- he almost definitely killed her so that she was out of his way, since at the time she had control of LuthorCorp.
In Star Trek: The Next Generation, The android Data has a "brother" named Lore, which turned out to contact an alien mass-killer entity and tried to let it kill everyone aboard.
An episode of Tales from the Crypt, appropriately titled "My Brothers Keeper", involves two conjoined twins, one of whom is a wholesome shy guy, while the other is a vain lectherous douchebag. Needless to say they don't get along.
Terminator: The Sarah Connor Chronicles features an AI version of this with John Henry, who considers the newly emerging Skynet to be his "brother" since they share the same code base. Given the prevalence of Biblical metaphors in this series, it's not surprising that the Cain and Abel comparison is explicitly brought up; John Henry wonders which of the two brothers he is.
Torchwood has Captain Jack and his (in this case younger) brother Gray. Gray is evil because he wants vengeance on Jack for accidentally letting go of him when fleeing from evil torturous creatures when he was little and letting him grow up being constantly tortured by them.
Damon (Cain) and Stefan (Abel) Salvatore from The Vampire Diaries, who've been in love with the same girl twice in the past century and a half. Currently subverted in that we've (almost) reconciled and save each other's lives more than they try to kill each other. Also Klaus (Cain) and Elijah (Abel), who parallel Damon and Stefan's relationship.
The Walking Dead has a gender-flipped version of this trope with Mika (Abel) and Lizzie (Cain) Samuels, two young girls who join the main cast in the prison around season four. It started out mildly, but then along came the Wham Episode "The Grove", in which Lizzie kills Mika in cold blood with a knife after she completely loses her mind towards the end of the episode. Harmful to Minors, indeed.
The battle between twin brothers Adam and Zachary is the entire premise of The Wanderer.
Wizards of Waverly Place. Although Justin, Alex, and Max all compete to win the absolute Family Wizard title, Justin and Alex are really into it, due to the burning, brotherly hate they have for each other, that grows more and more as episodes pass by. It's a serious case of sibling rivalry, even though it's not clear who is Cain and who is Abel in the relationship. Justin and Alex seem to constantly switch these roles.
Jack and Graem Bauer from 24, though it wasn't done nearly as well as it could have been, (but season six had bigger problems).
Kate and Marie Warner in the second season; Kate, the older one, is good, while Marie is working with the terrorists.
Omar and Farhad Hassan from Season 8; Omar is good, while Farhad betrays him to the extremists who don't want the peace treaty to go through.
Kamen Rider Gaim establishes this as the relationship between the supporting ally Mitsuzane and the Big Bad Takatora, though not in a direct confrontation. Mitsuzane hates Takatora and the empire he's building, subtly going against his back and insulting him and the lifestyle he wishes for him at every opportunity. Even as Riders, they don't have a massive conflict, since it takes Takatora a while to figure out his brother's a Rider and Mitsuzane half that time. It's only when Mitsuzane realizes why Takatora is building said empire that he joins his side... At least until Takatora's allies backstab him and leave him for dead. At that point, he sides with whoever is stronger, which includes the Overlords. Once Takatora got back and got word that Mitsuzane sided with them, that's when it gets to the brother murders brother that we all know and love, with Mitsuzane finally beating his brother... Unfortunately, they switched sides so now Takatora's the good guy and Mitsuzane's the villain.
In Witch Hunter, the rivalry between the three princes of the Bairong Empire gets very intense, even though one of them doesn't actually want the throne... one guess what happens. In a heartbreaking twist, the only actual fatality so far was a Mercy Kill done by one brother to free the other from a Grand Theft Me inflicted on him by their father. The third sibling is furious at the killer brother for doing this, while the killer hates his surviving sibling for allowing this horrible situation to happen in the first place.
Avenged Sevenfold (whose name was inspired by the passage of Cain and Abel) Have a song based on the passage, Titled Chapter 4.
The Finnish folk ballad Velisurmaaja (Brother Killer), where the mother inquires his son on what has happened, and the son confesses killing his brother: either for revenge from sleeping with his wife or slandering his mother.
The Puscifer song "Rapture" deals with a sense of hatred based on this.
Rapture my ass
You better hope he takes you
Before I do
About to drop you like Cain
Like Cain dropped Abel
"Buenos Tardes Amigo", by Ween, is a Mexican style ballad about a man hunting the man who killed his brother, who was adored by the villagers, the local ladies, and their mother. Of course, it was these qualities that led him to kill his brother and pin it on the poor traveller.
"Cain's Blood" by 4 Runner is a variant, which uses Cain and Abel as symbolism for the narrator's struggle between good and evil ("Half of my blood is Cain's blood / Half of my blood is Abel's").
Child Ballad #10, "Twa Sisters" and its myriad variations:
These sisters were walking on the bryn,
And the elder pushed the younger in.
"Oh sister, oh sister, oh lend me your hand,
And I will give you both houses and land."
"I'll neither give you my hand nor glove,
Unless you give me your true love."
Child Ballad #13, "Edward": A mother questions her son about the blood on his shirt; though he tries to lie, he eventually admits to having killed his brother. (Or, in some versions, "a boy" not related to him.)
Child Ballad #49, "The Two Brothers": The brothers are wrestling, one of them stabs the other. In some versions it's an accident, in most it's a murder with very unclear motives.
The Trope Namer is in The Bible (Genesis, chapter 4). Cain was a farmer, Abel was a shepherd. God wants a sacrifice, so Cain brings the produce of his farm and Abel brings some sheep. God preferred Abel's offering and rebuked Cain for being mad about it whereupon Cain lured Abel into a field and killed him.
Rudyard Kipling wrote a poem which claims that Abel provoked Cain by wrecking Cain's irrigation project to give the water to his cattle. (He also let them eat Cain's vegetables.) The last two lines of the poem explicitly state that the narrator thinks God's judgment on Cain was unfair.
The Bible also gives us Esau and Jacob, although they don't end up killing each other. And later, Jacob's son Joseph and his ten older brothers (mixing it with The Unfavorite).
Jacob's wives Rachel & Leah were this. Leah loved Jacob and bore him more sons but he favored Rachel. Understandable since Leah and her father tricked Jacob into marrying her and having to slave for another seven years to marry the woman he loved. Also Jacob chose Judah, his fourth-born, to become leader of his brothers. David was chosen to become King though he was the youngest.
Another Biblical example, Joseph's 10 older brothers sell him into slavery. In an odd twist, this later saves their lives when he (as second-in-command in Egypt) saves them all from a famine.
When Israel split in 2, Northern Israel is definitely Cain while Southern Judah is the Abel. Israel was wealthier and more influential but had the political stability of a game of Jenga while Judah was more spiritual and moderate. When these fight, Israel is usually the aggressor.
The Swedish Jonas Gardell made a point about this in his book About God, where he commented upon the fact that God showed a weird favoritism for younger sons, for no particular reason. It may have tied into favoring the humble, though, as the youngest son would inherit the least.
Romulus and Remus, the two founders of Rome in Roman mythology. Romulus was Cain to Remus's Abel.
Brother and sister war gods Ares and Athena would wrap entire nations up in their sibling rivalry.
It was short lived (only lasting nearly three months until Wrestlemania 25), but the intense feud between straight edged Matt Hardy and free spirited (and more popular) younger brother Jeff (a rare example of the older brother being the heel here).
The Undertaker and Kane, who alternate between hating each other and teaming up as the "Brothers of Destruction". Again, Kane is the younger brother (despite being bigger than the Undertaker), and usually the heel when they feud.
Heironeous and Hextor, the gods of Lawful Good and Lawful Evil respectively in Dungeons & Dragons, are brothers, and sworn enemies. Their appearances are radically different: Heironeous appears as a tall blonde human and Hextor, by contrast, is a six armed ogreish monstrosity. (Myths suggest that Hextor may have once been as handsome as his brother, and possibly even a force of Good, but was corrupted and degenerated into his current, ugly form.)
In the Forgotten Realms setting you have the twin goddesses Selûne and Shar. Having supposedly existed since the dawn of the universe and having been so close as to think of themselves as one being, they split apart on the issue of whether giving life to the barren universe would be a good idea. Selûne expresses her views on this matter by creating the Sun, which causes Shar to go Ax-Crazy on her and the entire universe, forcing Selûne to smack her with a Heroic Sacrifice bomb. Millenia later, Selûne's dogma urges you to trust in her radiance and know that all love alive under her light shall know her blessing, while the dogma of Shar features the promotion of misery for its own sake and the direct order to destroy anything Selûne might possibly be related to, in hopes of one day tearing apart the entire universe back into the sweet nothingness it was before this whole pesky 'life' thing. Evidently, they are now not so close as to think of themselves as one being, and the family reunions must be very awkward.
Playing out this trope to its bloody end, and incurring the consequences, made Ravenloft's Strahd von Zarovich into the most legendary Big Bad in Dungeons & Dragons history, appearing in every edition from 1st to 4th, and inspiring one of the game's most innovative and popular settings. Even the Demon Queen of Spiders never had an entire campaign-world named after her house.
Vampire: The Masquerade's 15 year long epic plot arc involves almost a hundred books devoted to the Cain(e) and Abel. Caine is turned into the first vampire for his crime, and thus begins so much purple prose, wangst and vampires gone to the extreme that an entire retread, Vampire: The Requiem, was required just to put an end to Caine and his fanbase. Undeterred, entire fan cultures and anti-fan cultures have sprung up around resurrecting Caine's importance to the series.
The best part was the anticlimactic "endgame" scenario where Caine rallies all of the thousands of vampires on Earth to destroy his rebellious children, the Antediluvians. Abel's ghost appears, says he forgives him, and Caine blows it off like so much dishwater. Caine is a jerk.
The Book of Nod contains a reinterpretation of the story that makes Caine seem much more sympathetic and pins most of the blame on the G-man instead. After Caine's first sacrifice failed to impress (god likes blood), he reluctantly chose to sacrifice his own beloved brother instead. But rather than being impressed at the depth of Caine's devotion, god just threw a fit and cursed him instead. So he ended up short one favourite brother AND god's favour.
Prevalent in Warhammer 40,000's backstory, especially the primarchs: Horus killing Sanguinius, Fulgrim killing Ferrus Manus and mortally wounding Roboute Guilliman, Leman Russ coming within a hair of killing Magnus the Red, Roboute Guilliman killing Alpharius (maybe)...
Warhammer 40,000 provides an extreme example of this trope (as it does in so many things...) is that entire armies of superhuman, genetically-engineered brothers are trying to kill each other (the Space Marines and the Chaos Space Marines).
The Leman Russ/Magnus the Red example above is a pretty interesting example. Leman Russ and his Space Wolves were tricked by Horus into attacking the chapter, which in turn would lead to Magnus becoming the evil of the two brothers. In short, they unwittingly caused a betrayal because they were manipulated into believing it had already occurred. Leman Russ himself was simply following orders, which soon turned out to have been made by the main traitor himself.
Although it didn't help that Russ was all too willing to kill Magnus due to his personal dislike bordering on hatred for him as a result of his aversion to sorcery (which Magnus was a master of). Magnus, for his part, also disliked Russ, and chose to simply slaughter the attacking Space Wolves rather than attempt to reason with them.
Then again, probably any primarch still loyal would have shunned Magnus for going against the prohibitation of sorcery set up by the Emperor. Leman Russ and the Space Wolves in particular are very superstitious, so their dislike against Magnus was not only fueled by his ignorance to the rules set up by the Emperor, but also for the fact that they use advanced sorcery on a high level, which the Space Wolves reacted very poorly to.
Fu Lang, the Big Bad of Legend of the Five Rings, is the younger brother of the gods who founded the Empire of Rokugan. After Fu Lang was corrupted by Jigoku, he sought to kill his surviving siblings and either destroy or corrupt everything they had built.
Wagner'sDer Ring des Nibelungen has some pretty messed-up brothers: Alberich enslaves Mime; the earth giant Fafner kills Fasolt over the ring Alberich created; and Hagen murders his half-brother Gunther over the ring.
Verdi's Il trovatore takes this to extremes. Ok, it takes everything to extremes.
Golaud kills Pelléas in Pelléas et Mélisande (Maeterlinck's play; Debussy's opera)
In The Skin Of Our Teeth, after Cain killed his unnamed older brother, his parents had his name changed to Henry in an attempt to protect his reputation.
In a rarer example of the younger sibling being the murderous one, Thrill Me has a song entitled, "The Plan", which is almost entirely devoted to the variety of ways Richard has thought up to kill his brother John. He doesn't, but only because Nathan points out that this trope makes for a really obvious motive.
There is a ridiculous number of Shakespearean examples for this trope:
Hamlet's father was murdered by his younger brother Claudius — and now Hamlet wants revenge. (The Kill Him Already element actually makes it better than it sounds.) William Shakespeare allegedly wrote his version of Hamlet because he wanted to improve on a previous botched stage version called the ur-Hamlet. We'll never know just how bad or good the ur-Hamlet was, because no copies are known to exist.
Age of Wonders has Meandor and his half-sister Julia. They got better, even becoming allies in Shadow Magic.
In Backyard Sports, Angela and Tony Delvecchio, siblings, play better on opposite teams in many games. This makes it tough to defeat one sibling using the other on a team.
Baldur's Gate plays this trope straight in the first game, then takes it to its logical extreme in Throne of Bhaal, wherein five of the six required bosses are siblings of the player and of Imoen, who may or may not be in the party.
Hinted at in The Binding of Isaac. One of Isaac's playable "siblings" is the literal Cain, and a power-up is a ghost baby named Abel. Whatever Isaac/Cain does, Abel does the opposite. If fan theory is to be believed, Cain and Abel represent Isaac and Maggy, as he feels guilty for hating her while she was alive, and blames himself for her death.
BlazBlue gives the example of Ragna and Jin, where Jin not only burnt down their home, but also presumably killed their sister, Saya, and to top things off, he cut off Ragna's arm. Though in Jin's defense, he was possibly possessed by the Big Bad.
Just pointing out that Saya wasn't actually killed there and then, and it was actually Terumi specifically who cut of Ragna's arm, Jin wasn't possessed at that point, but he did just stand there watching.
And in Continuum Shift's True Ending Ragna and Jin actually make peace with each other. Granted things are still shaky between them, what with Ragna being the destined Destroyer of the World and Jin the destined Antibody against him, but at least Jin isn't a crazy Yandere for Ragna anymore. Just in time for The Reveal of their missing little sister Saya being the Imperator of the NOL and the true Big Bad of the series — yes, she's the one giving Terumi and Relius their marching orders. She also hates Ragna, Jin, and her own Robot Girl clone Noel and calls them "scum".
Eventually revealed to be an aversion. That Imperator who gave order to the bad guys? Saya was just her vessel, the one who was speaking was instead someone unrelated: Izanami, the Goddess of Death.
In Boktai, Django later finds out Sabata is his (initially) evil, half-brother.
Borderlands gives us Jaynis and Taylor Kobb. Taylor hires you to kill his brother so he can take over Jaynistown...and then turns out to be even worse so you have to kill him too.
In Clive Barker's Undying, all the Covenant children fell to the curse of the Undying King, only to be resurrected as monstrous forms of their previous selves. They're out to kill Jeremiah, the last surviving son, to complete the curse.
There are also Bethany and Aaron, twins who utterly despised one another and were in constant rivalry. Bethany won, by chaining up her brother in a dungeon accessed through her room to be eaten by rats, and removing his jaw so he couldn't scream.
Literal example in the Command & Conquer series: Kane is hinted to be the (immortal) Biblical Cain, and Renegade even has his Temple in Sarajevo being built around the tomb of his murdered brother Abel.
Kasumi and Ayane of Dead or Alive. They were best friends as children, especially given Ayane's status as a village pariah. When they discover that they are half-sisters and Ayane is the product of rape, Ayane turned on Kasumi out of jealousy that the former was raised in luxury and beloved by everyone while she was scorned and hated by the same people, and is currently the one tasked with assassinating Kasumi after she left the village to pursue Raidou. Unlike most examples, however, Ayane isn't evil, just Anti-Heroic, and as of the ending of Dead or Alive 5, they seem to have reconciled.
Dante and Vergil of Devil May Cry. In the original series, it was primarily Dante and Vergil's differences in regards to which side of their nature they embraced, while in the new game, it is more a question on whether the Nephilim should let humans decide their own fates (Dante) or rule over them (Vergil).
It's quite literal in Devil Survivor, where Naoya, the protagonist's older cousin, is revealed to be the original Cain, while the protagonist possesses Abel's essence (along with a bunch of other people, apparently). The dynamic's a little different though, as Naoya does not want to hurt the protagonist: He wants to make Abel reject God and become the king of Bel, and serves as a Stealth Mentor for most of the game to nudge you in that direction. He will only fight the protagonist's group in the Law and Atsuro endings, and in the latter case it's more a Secret Test of Character to see if the protagonist has the will to enslave the demons.
This trope is what led to Fuuka's murder in Disgaea 4.
This comes up several times in Dragon Age II. Near the end of Act I, Bartrand succumbs to greed and the lyrium idol's curse and tries to kill Varric to avoid sharing the wealth. Varric can either kill Bartrand as payback, kill him to save him from the lyrium idol's corruption, or put him in an asylum to care for him. In the "Fool's Gold" sidequest the middle brother Iwan leaves his older brother Emerys and his younger brother Merin to the darkspawn so he can claim a valuable magical sword for himself. Varric will even mention that this story is awfully similar to what happened to him. In the endgame, if Hawke supports the Templars, he/she may end up fighting and executing Bethany if she joined the Circle. Oddly enough, Hawke's more antagonistic sibling Carver will never fight Hawke and even defends him/her as a Templar when Meredith orders him to kill Hawke.
The Elder Scrolls III: Morrowind gives us Vedam Dren, the noble duke of Vvardenfell, and Orvas Dren, the leader of the xenophobic criminal organization, the Camonna Tong. Vedam doesn't want his brother killed, but isn't overly angry if it comes to that, while Orvas... is planning to murder his brother, which you can use to blackmail him if you find the implicating letter.
Exit Fate also contains two such siblings (in this case, twins of opposite genders): Brunhild and Daniel. Clearly, SCF likes putting siblings at odds with each other...
The premise of Fable III. Big Bad Logan is the tyrannical ruler of Albion you must overthrow and the son of the previous game's player character. He also happens to be your older brother. Depending on your own approach, you can potentially be better or worse than him.
In FEAR, it's explicitly canon that Alma (the homicidal female ghost) is the Point Man's mother, Paxton Fettel (The Dragon) is the Point Man's brother, and the Mad Scientist responsible for the creation and birth of both the Point Man and Fettel was Alma's father Harlan Wade, who ruthlessly exploited his naturally born daughter's psychic abilities in an attempt to create Super Soldiers. All in all they're a Big Screwed-Up Family.
Fear Effect: Retro Helix. Glas and Drew, with Glas being Abel and Drew being Cain. Rain and Mist, with Rain being Abel and Mist being Cain. Subverted in both cases, with Glas and Rain not only surviving the attempts on their lives, but end up killing off Drew and Mist.
This happened to no end to Cecil in Final Fantasy IV. His best friend and comrade in arms who betrays him is actually 'named" Cain. (Kain in the original North American release, because I guess it was too obvious otherwise?). The second time it was revealed that Big Bad Golbez was his actual brother. Of course, it was revealed in the end that both were actually just being mind-controlled by the Man Behind the Man.
In the DS version, it is revealed that Golbez, known way back as Theodor, was compelled by Zemus to abandon his baby brother in the woods outside Baron. If you're wondering why Cecil thinks the king as his own father up until The Reveal, now you know.
Path of Radiance's Mad King Ashnard probably fits. What with killing all of his other siblings and all.
Subverted in the first game, in which the token red and green cavaliers were actually named Cain and Abel, despite not actually being involved in any such feud. And in fact, Cain remains loyal to Marth, never gets jealous at the luckier-with-ladies Abel (who got Palla and Est having a crush on him and he married Est), and in Mystery of the Emblem, Abel was instead first seen as an enemy, betraying Marth... although that was because the enemy held Est hostage.
Kratos actually has several of these in God of War, being a son of Zeus and all, the foremost being Ares, who tricked him into killing his wife and daughter. In only two cases, however, is the connection actually remarked upon; with Hercules, a "Well Done, Son" Guy who hopes to surpass Kratos, and Athena, who plays the role of ally, reluctant enemy, ally again, and finally Bitch in Sheep's Clothing.
In Grandia II the main character must fight his older, more skilled, possessed brother.
Roland and Archibald Ironfist of Heroes of Might and Magic. Though, ultimately, neither brother is willing to go all the way: in their respective endings in Heroes II, Archibald gets Taken for Granite and Roland is imprisoned in the western tower (canonically, the first is what happened), and when next the two brothers meet, Archibald helps save Roland, taking him to Roland's wife despite knowing full well that she has every intention of executing him should she get the chance — Roland, in turn, intercedes on Archibald's behalf and gets the sentence down to exile.
In Kid Icarus, Palutena and Medusa, sister goddesses of light and darkness respectively, have this type of relationship. It's not hard to guess which one is the evil one. It's subverted in that Palutena did not kill her herself, she only turned her into a monster and banished her. The angel Pit finished the job.
Last Scenario has Castor and Ethan, respectively, including the age rule. However, it's pointed out that the younger of the two plays the role of an older sibling in many respects, which may make this a slight variation on the usual set-up.
League of Legends has two pairs. Kayle and Morgana are ancient angels locked in an Order Versus Chaos war with each serving the league in hopes of gaining the power to defeat the other. Nasus tutored scholars in mystic arts while Renekton judged if they were worthy of learning them, until the evil he saw in their minds drove him into insanity and constant rage and he attacked Nasus as the only one who could kill him.
There's a sidequest in the first Mass Effect game in which Nassana Dantius, an asari diplomat on the Citadel, asks you to rescue her sister, Dahlia, from slavers. After you defeat the slavers, you find out that Dahlia was the leader of the slaver group. Who you killed. Nassana wanted Dahlia dead because having a slaver sister would possibly hamper her career. This is actually kindof funny due to the fact that her voice actress voiced Azula.
The Snake Brothers (okay, "Les Enfants Terribles", strictly) in the Metal Gear series. Liquid seems to enjoy the rivalry immensely. Perhaps a littletoomuch.
It's no coincidence that their mother's codename is EVA. She's explicitly linked with Eve, and not only by reference to her sons - this is her on the boys' father, who at the time went by the codename Naked Snake: "But... it was I who tempted the Snake, and got away with the forbidden fruit of knowledge."
The trailers for Modern Warfare 2 explicitly invoke the murder of Abel, with Makarov talking about the blood of those killed by the United States and the UK crying out from the earth, and noting that they cannot hear the cries because they do not come from their own soil....but they will.
Bi-Han (Noob Saibot) and Kuai-Liang (Sub-Zero II) from Mortal Kombat.
In Mother 3, Lucas must fight his brother Claus, who was killed, reanimated, and brainwashed into being the Pig King's loyal minion. When Claus snaps out of it, it's too late.
In SaGa Frontier, there are Blue and Rouge, twins who're told to kill the other after mastering as much magic as possible. Who wins is irrelevant, since they turn out to be the same person, Split at Birth.
The obscure PC game Sanity Aikens Artifact feature such a storyline with someone named Cain as the protagonist and the so-called foster brother Abel as the final boss.
In SoulCaliburV, Sophitia's children Patroclus and Pyrrha are driven to this thanks to being egged on by Soul Calibur and Soul Edge respectively. Fortunately, the siblings are strong enough to eventually overcome the influence of both swords for each others' sake.
Soulcalibur IV Sophitia becomes the Cain to Cassandra's Abel, but not willing because she has been Forced Into Evil.
In Starsiege, two mech pilot brothers are codenamed...Icehawk (the older, a cold-blooded by-the-book pilot who is loyal to the Emperor) and Phoenix (the younger, a prodigy pilot who has a knack for escaping from impossible situations and joins the Mars Rebellion). They are and are not actually related: Icehawk's real brother was critically injured in an accident and the Emperor secretly had his brain replaced by the organi-mechanical brain of his own son, as a way to continue his son's existence. Indeed, a hidden sect of people in the game world do this with their brains all the time, choosing children with life-threatening injuries and swapping brains with them while they're hospitalized.
Street Fighter IV. It's a definite shout out to the bible, a hero being named Abel, only the Cain is named Seth. It's made very obvious that Abel is a product of S.I.N. experiments like Seth, in both his Ultra Combo(Where his eyes change color to resemble Seth's), Abel's ending, and both of their win quotes against each other in Arcade Mode.
According to Word of God, Seth was indeed originally going to be named Cain, but this was changed due to some other fighting game having a character with a similar name. It also helps that Seth is the name of Capcom's senior manager, Seth Killian, also known as "S-Kill".
This also works for Akuma and Gouken.
Redmond and Blutarch Mann from Team Fortress 2, to the point that not even death can stop the rivalry between them; when they're both killed by their long-lost brother Gray Mann in the comic prologue to the Mann vs. Machine update, their ghosts later hire the mercs to send the other brother's corpse to Hell so they can legally be the winner of the war between them as part of the 2013 Halloween event.
In the fashion of the Tekkaman Blade example, Super Robot Wars Compact 3 gives us sworn brothers Folka Albark (the elder, main protagonist) and Fernando Albark (the younger rival). Then there's their older brother Altis Tarl, also in the enemy's side. Subverted because Fernando and Altis are not outright evil, they're just Folka's enemies on circumstances.
The first Original Generation game has brothers Raideisse and Elzam Branstien fighting for the first half of the story. Mostly because they happen to be on opposite sides of a war, but it also brings out a measure of animosity, mostly on Rai's part, over the death of Elzam's wife (long story), whom it's suggested Rai was in love with.
In Super Robot Wars NEO, Amane Inaba when possessed by Larva is the Cain and Kakeru Inaba is the Abel.
Kazuya Mishima and Lee Chaolan fit this trope as well since, technically Lee is Heihachi's son through adoption.
Likewise with Kazuya and Lars, since Lars is the son of Heihachi and a Swedish mistress.
Jacky and Sarah Bryant from Virtua Fighter had to go through this. In the first two tournaments, J6 brainwashed her and had her try to kill her brother. After she was freed from their control, her motivation for joining recent tournaments was to fight and defeat her brother, not knowing this is all part of J6's plot.
In the Warcraft universe, night elf twin brothers Illidan and Malfurion Stormrage are Cain & Abel respectively. Illidan became a demon literally due to his consuming the power of the Skull of Gul'Dan and figuratively due to his addiction to magic.
His jealousy over priestess Tyrande Whisperwind choosing his brother over him was actually the plot point that fixed their 10,000-year-old-feud. Events spanning throughout the third game and its expansion culminate in the brothers teaming up to save Tyrande and making up before Illidan leaves Ashenvale (for reasons not revolving around the Night Elves).
In World of Warcraft, this happens with Krenna and Gorgonna in Conquest Hold. Krenna, the commander, wants to wage war on the alliance, and the more reasonable Gorgonna doesn't want it to happen. In the last quest in the chain, you fight alongside Gorgonna against Krenna and her bodyguards, killing Krenna and allowing her to take command. Despite the fact that she knew killing her was necessary, Gorgonna mourns the loss of her sister.
During the events of Wolfheart, Jarod Shadowsong (Abel) and his sister Maiev (Cain). Near the end of the novel, they had a bloody confrontation when he had discovered she had captured and planned to kill Malfurion Stormrage; he couldn't bring himself to kill her and she fled.
Based on a line of dialogue from the finale of the Sunwell Plateau raid, possibly Velen (Abel) and Kil'jaeden (Cain). Noteworthy in that this particular rivalry has had repercussions affecting the inhabitants of many planets.
The ridiculously gory and difficult adventure game Waxworks was built around this concept. Your family was cursed so that one of every set of twins becomes evil, and you have to go back in time using the titular waxworks building to kill the worst of them and break the curse. Your own brother is incapacitated before and throughout the game, and part of your goal is to save him, but other than this, the "evil twin" aspect isn't played up much: the evil brothers of the past include Jack the Ripper, a necromancer who looks far older than his good twin, and a human/fungus mutant who doesn't even resemble a human anymore.
An adopted example: Franziska von Karma from Phoenix Wright: Ace Attorney has some severe issues with her adopted "little brother" Miles Edgeworth. She's determined to outdo him in nearly everything, especially prosecuting, and is unhappy that she won't get to prosecute before he does (even though she's seven years younger than he is). Edgeworth doesn't seem to care very much, which only infuriates Franziska more.
In Apollo Justice: Ace Attorney, Kristoph and Klavier Gavin are respectively Cain and Abel, with Kristoph being an Amoral Attorney who is responsible for Phoenix getting disbarred, and Klavier being a more moral prosecutor..
Shiki and SHIKI in Tsukihime. Best friends, adopted siblings. Then SHIKI goes crazy because Roa possessed him plus his inversion went off. Still, turns out if they're able to meet on friendly (Kagetsu Tohya) or semi sane (Kohaku's route) terms they still actually get along quite well, and he's not really that bad a guy.
Also from the Nasuverse are the Aozaki sisters, Touko and Aoko, although the details aren't clear.
Umineko no Naku Koro ni has four siblings in one Big Screwed-Up Family. It also subverts the usual "brothers or sisters" rivalry. Krauss is largely resented by his younger siblings, particularly Eva, who actually takes her resentment out on Krauss's wife, Natsuhi. All four of them are pretty messed up, though, due to being raised by Kinzo, and at certain points, even Krauss and Rudolf admit that they wish they'd been better older brothers to Rosa.
Twin brothers Leni and Seizh of Under The Moon seem to get along fine at first, but Seizh's simmering inferiority complex regarding his more successful sibling is itching for an outlet.
Dominic Deegan: Oracle for Hire sometimes pits Dominic and Gregory against their necromancer brother Jacob. Early on, there was an interesting twist: Dominic hated Jacob, but Gregory still wanted to believe the best of him.
Luna's relationship with her sisters was also like this for a while, but the three eventually decided to try and at least tolerate each other after the rest of their family got themselves killed with their petty fighting.
To a much lesser extent, Ariel and her older "sister" Syphile. Syphile was forced to become Ariel's Governess, despite having never been trained in childcare. After years with a Babysitter from Hell, when asked what she would most like to do, the ten - year old Ariel replies "kill Syphile".
Another example with Ariel is with her half-sister Kalki, who goes so far as to stab Ariel in the hand and then chop off her arm they very first time they meet.
In Homestuck, the Cherub Caliborn loathes his "sister" and split personality Calliope. He murdered her dreamself before he even started his session of Sburb. As Lord English, he is still hung up on his hatred of his sister. He destroys entire dream bubbles — tearing reality apart in the process — hunting his sister's ghost so he can finally make her Deader than Dead. Arguably, everything bad in the entire story can be traced back to Caliborn's desire to destroy his sister and everything his sister loved.
Elan created a situation like this between his puppet Banjo the Clown and another puppet Giggles the evil Clown god of slapstick. Since deities are powered by belief, the two of them are actually gods now that an entire orc tribe worships Giggles and Banjo is his equally powerful rival. Elan liked the orc high priest of Giggles' suggestion that the two were brothers.
Nale is confused when he finds out that Roy and Julia Greenhilt actually get along. He thinks this trope is normal. And so does his girlfriend.
Cain and Abel from Serpamia Flare. A bit of a literal demonstration of this trope in the names; Cain has great trouble talking about his brother in Chapter Two and refers to him in past tense, while Abel expresses extreme distaste/anger at the mere suggestion that Cain may be involved with a situation at hand at the end of Chapter Two. They seem to have some past issue, though a hint in Chapter Three suggests the two brothers weren't always on bad terms.
Oasis and Kusari in Sluggy Freelance. Oasis actually killed Kusari once, but she got better.
Admittedly, it's unclear if their siblings in the traditional sense of the word, or if it's some weird clone/other-half-of-a-supernatural-force thing or what-have-you.
Can we mention everyone's favorite Yaoi webcomic, Starfighter? They're not brothers or even friends, but Cain is the codename of the violent Seme and Abel is the much nicer Uke.
8-Bit Theater's Black Mage once watched his own blind brother stumble around an uneven room laced with knives and tiger pits, even going so far as to push him when it seemed said brother would survive the ordeal. Of course, it would have been cruel to let him live after what he did to his eyes...
In The Gamers Alliance, both Refan and Zarnagon and Leraje and Ronove are this as they work for opposite sides in the war.
Cortez and Mendoza Cardinal from The Leet World. Cortez was the leader of the Ochos Muertos terrorist group, Mendoza his second-in-command. When Cortez rejects Mendoza's plans to gain power and wealth, a furious Mendoza betrays brother, taking control of the Muertos and leaving Cortez blind. Years later, he hires the Domination Guy to kill Cortez, and when that fails, he concocts an elaborate plan to enter the House and finish his brother off.
Played with when Team Dad Westheimer kills Mendoza in the final challenge, saving Cortez's life. However, Cortez (who had sworn to have his revenge on his brother for blinding him) is furious, and vows to avenge Mendoza's death.
Westheimer: I don't care about this feud of theirs. Probably goes back to "who did Mommy love more?"
In New Vindicators, siblings are often at odds, its just that kind of series. Phobos and Deimos are twin brothers, and Deimos wants to be the one who kills Phobos, while Phobos' problems are less personal, and more because Deimos is a bad guy. In the European Academy, this pops up again, with the younger sibling being the evil one, wishing to make their older sibling suffer as much as possible, rather than outright killing them.
They're both pretty much immortal. They've probably met again long before the SCP found them, and sometime after The Bible's story with them.
Jeremy and Bran from Shadow Of The Templar. While Jeremy still cares for Bran and wants him to reconcile with their father, Bran despises Jeremy for being a better thief than him and having stolen his father's attention from him despite being "only" a foster son. Whenever the two meet, it's always highly uncertain whether Bran will listen to Jeremy or kill him out of spite. It's even all but said that they had sexual relations in the past, which really makes their current relationship a helluva complicated one.
Another example would be Josee Trembley and Remy Kim of v4, who suffer from a Sibling Rivalry as a result of both siblings trying to win their mother's love as a result of both seeing themselves as The Unfavorite. Currently somewhat played with, as Josee actually wants either one of them to live to return home, and it looks like a team-up is in the works.
In the episode "Gonna Getcha" of The Angry Beavers, the Beaver brothers watch a movie with a Cain and Abel plot. Daggett gets absolutely loaded with Paranoia Fuel.
In Avatar: The Last Airbender , the royal family of the Fire Nation exhibits this with two sets of siblings. As above, in both cases the younger sib is the outright sociopath of the two. On one of the occasions where Azula outright attempts to kill Zuko, her brother, she shouts, "I'm about to celebrate becoming an only child!"
In season 3, Sozin and Roku are revealed to have been as close as brothers in their youth. Then Roku went away to become the Avatar, and Sozin became Fire Lord and decided that what the world really needed was to be conquered by him. They'd grown apart rather, and Roku kept shutting Sozin down flat whenever he brought these ideas up. Eventually Roku violently halted an invasion of the Earth Kingdom, which Sozin interpreted as a permanent breach of their old friendship...and therefore betrayed Roku to his death during a volcanic eruption, leaving him free to launch his world conquest.
And in The Legend of Korra, we have Amon/Noatak and Tarrlok. Neither's exactly good, but the younger, Tarrlok, is much closer to the heroes' side by the end of things than Amon is. Though unlike Azula and Zuko, at the end they really loved each other.
Book 2 has Korra's father Tonraq and his brother Unalaq, the latter going to various lengths to eliminate the former and bring Korra to his side.
To add to the fun, it's implied that Phaeton's villainy is an attempt to compensate for having betrayed Marsala during the First Neosapien War fifty years ago.
A rather lighthearted example appears in Foster's Home for Imaginary Friends. The imaginary friends Imaginary Man and Nemesis (short for Nemesister) were created by a boy and his Bratty Half-Pint sister respectively — the sister created Nemesis just to bug her brother and Imaginary Man. Their feud continues after the now grown up siblings adopt Imaginary Man and Nemesis for their children. Ironically enough, the brother adopts Nemesis thinking she would be the perfect friend for his daughter and the sister adopts Imaginary Man thinking he would be the perfect friend for her son.
Terrence and Mac can be viewed this way.
Corey and Trina from Grojband, though most of the animosity comes from the latter.
Masters of the Universe: Big Bad Skeletor was supposed to secretly have once been Keldor, the brother of King Randor (and thus Prince Adam/He-Man's uncle). This was never officially revealed in any canon but has been confirmed as the intended outcome of the original minicomics that had already begun to anviliciouslly hint at it when the toyline was axed. Skeletor's past as Keldor was depicted in He-Man and the Masters of the Universe (2002) and the backstory of he and Randor being half-brothers was discussed by the writers on a DVD commentary as being an additional reason for their more specific & personal animosity in that version.
Megaman and Protoman are this in the Ruby-Spears Mega Man cartoon.
Princess Luna and Celestia form a rather complicated example in My Little Pony: Friendship Is Magic. Luna got corrupted by an outside influence and when that was gone Celestia immediately offered to return her to power.
Also, in the episode, "One Bad Apple", Babs Seed, who is the cousin of Apple Bloom, bullies the Cutie Mark Crusaders after she joins Diamond Tiara and Silver Spoon. However, when it turns out that she only did that out of fear of being bullied herself, she and the CMC make amends.
The relationship between Mojo Jojo and the girls in The Powerpuff Girls could easily be seen this way, especially after it's revealed that it was Mojo who caused the accidental addition of Chemical X into the perfect girl mixture. Interestingly enough, it's he who has a Villainous Breakdown when the truth is revealed...
ReBoot's principal villains, Megabyte and Hexadecimal, are brother and sister, yet they are always trying to kill each other. When an incredulous Bob asks why, Hexadecimal casually explains that it's just "sibling rivalry."
Thanks to a Retcon, Megabyte and Matrix fit this too. Matrix's dad, Wellman Matrix, is responsible for the "birth" of Megabyte. Megabyte even calls the nullified Wellman "father" so this makes Megabyte and Matrix brothers. Good thing Matrix doesn't know this since he has a problem with viruses.
Robot And Monster has Robot and his Jerkass older brother Gart, who considers himself the Always Someone Better to Robot and will do anything to run afoul of him, such as buying the main duo's apartment and using his power to wildly lower and raise the temperature or creating a Pole-O team to go up against his.
In Shadow Raiders, Femur arranged for his brother to be locked away in the prison planet, a hellhole where the Cluster's worst war criminals were sent to, where he was subjected to horrific tortures and expected not to survive. Considering Femur had to bribe the soldiers that were dragging him away so he wouldn't be executed, Sternum had it coming for A: trying it and B: not using more loyal guards.
In Teenage Mutant Ninja Turtles (2003), adoptive brothers Hamato Yoshi and Yukio Mashimi become this when Mashimi, in a fit of jealousy, kills fellow adoptee and love triangle member Tang Shen. Afterwards, Yoshi kills Mashimi in revenge.
This is an adaptation of the story of Hamato Yoshi and Oroku Nagi from the original Turtles story, which led to quite the Cycle of Revenge when Nagi's younger brother Oroku Saki, who would later become the Shredder, murdered both Yoshi and Shen in vengeance for Yoshi killing Nagi.
Starfire and Blackfire of Teen Titans, who still look like a parallel of Queens Elizabeth and Mary Tudor, even though Glen Murakami admits that they watered down the much more intense rivalry of the original comics into a more kid-friendly, "I Dream of Jeannie/Bewitched kind of way." If you're even slightly familiar with the comics, you'll know what he's talking about◊.
Played with by The Venture Bros. where Thaddeus "Rusty" Venture eats his twin brother Jonas Venture, Jr while they were still fetuses. Jonas survives and later escapes, and attacks Thaddeus but gives up because he can't kill his own pathetic brother. Jonas finding his true calling as a heroic man of science quickly becomes a success financially, and with the ladies. Its basically implied that both would be successful if Thaddeus became a super villain, and arched his good brother.
As the series progresses it's hard to say who is Cain and who is Abel - Jonas Jr. is certainly living up to their father's legend, but we start to see that Jonas Sr. had a pretty sleazy side.
Baby sharks developing in the womb will fight and eat each other before they are born. Only two sharks end up being born, and that's only because there are two separate wombs.
The Banquet of Nyköping 1317. The Swedish king Birger had invited his younger brothers, dukes Valdemar and Erik, to Castle Nyköping to feast at Christmas. After everyone had gotten drunk, king Birger imprisoned his brothers, put them in the oubliette of the castle and (so tradition says) threw the key into the nearby river. The dukes died from starvation. A large medieval key was found near the castle in 1847.
Though it will never be proven, it's extremely likely that Cesare Borgia (son of Pope Alexander VI and then-Cardinal of Valencia) murdered or ordered the murder of his younger brother, Giovanni (Juan) Borgia, the Duke of Gandia. Juan was a hopelessly inept military commander, favored by his father; Cesare hated him and wanted his position. Being a magnificent bastard in more ways than one Cesare actually excelled at the job until his father died and ran out of funds.
Similarly, chicks of several species birds of prey are known to murder their siblings while in nest.
An interesting historical example is the murder of King Erik IV of Denmark by his brother, Abel. Chroniclers called the murderer "Abel by name, Cain by deeds."
In 16th century Sweden, king Erik XIV starts behaving like he is insane and is deposed and imprisoned by his younger brother Johan after an insurrection. Johan makes himself king, while Erik's son and heir to the throne Erik Jr disappears abroad. Later king Johan has Erik Sr poisoned to death.
Byzantine Emperor Isaakios II adored his brother Alexios and gave him many honors. Alexios repaid him by staging a coup, putting out his brother's eyes, imprisoning him, and crowning himself emperor as Alexios III. Isaakios' teenage son managed to escape his uncle's tyranny and showed back up on his doorstep with an army: The Fourth Crusade. Things went From Bad to Worse shortly thereafter, and Constantinople passed out of Byzantine hands for almost sixty years.
Following the death of John VI of Portugal, his oldest son Pedro (then Emperor of Brazil) briefly succeeded to the throne. After abdicating in favor of his infant daughter Maria, Pedro's younger brother Miguel declared himself King, which led to the Portuguese Civil War (alternatively known as the War of the Two Brothers.) Six years later, Maria was returned to the throne, Miguel and his family were forced into exile, and Pedro died shortly after achieving victory.
The Minamoto brothers, Yoritomo and Yoshitsune, in feudal Japan.
The Mughal dynasty had a lot of these. A prominent example is the murder of Prince Dara Shikoh, the King's oldest and favorite by Aurangazeb, a younger son.
The Ptolemys of Egypt were great proponents of this. A rather famous one Cleopatra, was a big fan.
The death of a Sultan of the Ottoman Empire regularly resulted in his male sons eliminating each other until only one legitimate heir was left.
One of the greatest Emperor of Tang Dynasty, Emperor Tang Taizong is this trope. In an infamous incident known as the Xuánwǔmén zhī biàn, he ambushed his older brother Li Jiancheng (the crown prince) and his younger brother Li Yuanji. He killed his older brother personally, forced his father to make him crown prince only to make it proper for his father to surrender his throne to him just two months later.
Oh ya, he also killed the sons of both Li Jiancheng and Li Yuanji, and made Li Yuanji's wife his concubine. That's just some badassery.
And it's true that he's a noble Emperor.
Li Jiancheng and Li Yuanji were also plotting against Li Shimin (brother number two). Li Jiancheng was jealous of his second brother because Li Shimin was more capable in almost every respect, and may have feared losing his crown prince position to him as a result. He recruited his third brother who was similarly jealous, and the two of them were in fact preparing an ambush/attack of their own at the very moment they themselves were ambushed. Or so it has been recorded. (History tending to be written by winners who become emperors....)
Played definitely straight in the Wars of the Roses in 15th century England. It effectively meant the extinction of the Plantagenet dynasty and whole family line.
The most specific example is George, Duke of Clarence. He is largely overlooked, with Richard being seen as the treacherous brother of Edward IV. However Clarence helped a rebellion against Edward by the previous royal family, then switched sides again. Considering this, it isn't surprising Edward didn't trust him. Clarence continued to cause trouble for Edward, apparently thinking he wasn't getting enough influence, and was finally executed.
William the Conqueror's children. Henry (who may have [that is: almost certainly] had his other brother William Rufus murdered to gain the throne of England, staged a coup in Normandy against his eldest brother Robert, while the other was on crusade, and later imprisoned him.