Freezing. In every battle with the Monster of the Week, The Nova ends in massive death tolls, which increase with every battle as the Novas evolve and improve at a rate mankind just can't keep up with. The tiny part of the population able to fight The Nova is dwindling ever quicker and getting harder and harder to replace, made worse because the entire population able to fight Novas is made up of Child Soldiers who, on top of risking life and limb, die at a young age anyway because of the use of their powers.
At the end of Hellsing, The Major and every last one of his Millennium vampire soldiers have been slain, but he dies content. The cost of his defeat was the destruction of London, with almost all of its population dead overnight, Alucard is apparently destroyed, Pip is dead, Walter dies a traitor, and Integra is now missing an eye.
Mazinger Z: After a long and hard battle, Kouji defeated Dr. Hell with Mazinger Z. However, the Mycene immediately attacks without giving any time to rest and he is unable to do anything to stop them. Mazinger Z, Venus A, Boss Borot and the Photon Research Institute are easily destroyed (and several world cities, including Tokyo, in the movie). Kouji is saved by Tetsuya and his Great Mazinger, who claims that Mazinger Z isn't needed anymore.
And in Great Mazinger, the heroes finally defeat the Mykene army... but it was due to the Heroic Sacrifice of Prof. Kabuto, Kouji and Shiro's biological father and Tetsuya and Jun's adoptive father. Despite the victory, nobody felt victorious; in fact Tetsuya blamed himself for his father's death, and rightly so. In one of the adaptations, Tetsuya himself bites the dust.
In Slayers, the Koma War (translated variously as "Dark Lord's Resurrection War", "War of Demonic Invasion", "War of the Monsters' Fall") a thousand years ago ended badly for pretty much everyone. Ruby-Eye Shabranigdu destroyed Aqualord Ragradia... but was permanently frozen in the Grim Up North, all his power sealed. Half the Golden Dragons in the world were slaughtered... but Mazoku also suffered the deaths of two Priests and two Generals (who are irreplaceable), as well as the desertion of Chaos Dragon Gaav and all serving him. Even aside from Gaav's outright betrayal, without Shabranigdu organizing them, the Five Retainers couldn't get along and started bickering amongst each other over the best way to end the world. Humans suffered devastating losses, including losing the ability to perform Holy Magic and being confined to a single continent by the Mazoku God-Sealing Field, but on the other hand started developing increased levels of Black and Shamanic Magic. In short, nobody won. Thus, in the novels, when Dynast Grausherra decides to bring about the resurrection of Ruby-Eye through a second Koma War, even his fellow Mazoku are opposed to the idea.
The ending of Death Note certainly feels like one of these. Soichiro Yagami, one of the only truly good characters in the series (according to the artist himself,) is dead, L is dead, Mello is dead (although that was just as planned), poor Matsuda's probably going to need some serious therapy, there is no afterlife (at least in the manga), god knows how many NPCs are dead, and a year later, the world's practically returned to normal. Kira barely changed anything. Ouch.
The manga's ending is less Pyrrhic for Light though, as there is still a cult of followers worshiping him, even though everything else returned to normal.
The movie version is only marginally better. L gains 23 days, but he still dies. Kira is stopped sooner, but the world still goes back to normal. There's still no afterlife (at least for Death Note users). This time, he survives, but Soichiro's the one that needs therapy now.
The ending of the Chapter Black arc in YuYu Hakusho has Yusuke defeat Sensui, except Sensui was already dying and the demon gate was opened just so he could die honorably. In addition, said demons turned out to mostly be nobler than the humans Yusuke was to protect, and The Spirit World did indeed turn out to be corrupt.
In Bleach, Uryu's fight with Mayuri Kurotsuchi ended with Uryu defeating Kurotsuchi at the cost of having all of his powers semi-permanently sealed away.
When Ichigo wins a fight by giving into his Superpowered Evil Side. Yes, he won, but in doing so he traumatized one friend, stabbed and tried to kill another, and brutally mauled his opponent to death.
Also, his final victory against Aizen. Aizen can only be sealed away and imprisoned meaning there's always a chance he could return. Meanwhile, Ichigo sacrificed his powers and his ability to be a substitute Shinigami. Thinking he has no right to complain about this, he tries to go on with a normal human life for 17 months, his grades slipping and not planning for his future because he's unable to face up to reality that having the power to protect is an integral part of who he is, without which he's reduced to simply existing instead of actually living. It takes another substitute shinigami shaking up his life to make him face and accept the truth.
Sajin Komamura sacrificed his heart in order to become stronger and, for a while, making him incapable of death. He then proceeds to curb stomp Bambietta. However, he ends completely turning into a wolf/dog thing and might be dead.
Defeating the D-Reaper in Digimon Tamers was this. Basically, the only way to stop it was to use a weapon that damaged their own Digimon to the point they had to go back to the Digital World or die, and by the time it was ready the D-Reaper had already destroyed a good portion of both the Digital and real worlds. To rub salt in the wound, the weapon couldn't even kill the D-Reaper — all it did was let the Tamers seal it away and pray to the Sovereigns that it never broke out.
The anime ending of Chrono Crusade qualifies. Chrono and Rosette manage to save Joshua and defeat Aion, but Joshua is badly brain damaged and can't remember them, Chrono and Rosette are badly injured during the final battle and die together six months later, Satella kills her sister and herself in order to stop Fiore from taking Joshua back to Aion, Remington is left broken and filled with regret, Aion's plans cause the Great Depression, and in the 1980s Remington witnesses a man that appears to be Aion take out a gun and shoot the Pope. It's also implied that Aion is revived by humanity's sins and will live on as long as sin exists in the world, meaning that Chrono and Rosette's sacrifices only seem to stop Aion temporarily.
Whether you believe Tabris the 17th Angel allowed Shinji to kill him because he truly respected/cared for Shinji, or because he wanted to make Shinji suffer as he died, it's indisputable that the destruction of the last Angel in Neon Genesis Evangelion ruined the last of Shinji's self-confidence and mental stability. It gets worse in the Movie, when we realize the Angels are actually NOT the real threat as his Magnificient Bastard of a father AND SEELE an Ancient Conspiracy begin their plans for World Instrumentality.
Taken Up to Eleven in Rebuild of Evangelion. In the second movie, Shinji attempts to rescue Rei's soul from Zeruel's core after the former has been consumed by the angel. He fulfills this goal to an extent, but at the cost of triggering the Third Impact and kickstarting the end of the world. In the end, it is revealed in the third movie that he hadn't even been able to save the Rei he wanted to save after all.
After winning the previous Gundam Fight, Master Asia looks back and is horrified by the carnage and the damage he and the other participants have caused. He becomes bitter at humanity's willingness to go through such lengths and has thus chosen to be extreme in his own way.
Domon himself. He defeats the Devil Gundam and saves Rain and his father, but in the process he loses his mother, brother (twice over), and mentor in true Tear Jerker fashion.
At the end of One Piece's Paramount War arc, the Navy succeeds in their stated goal of killing Ace and Whitebeard, ostensibly proving the strength of their justice. Yet they lose so, so much more. To whit;
Before the War began, Straw Hat Luffy, trying to free Ace, sneaks into Impel Down, and ignites an unprecedented prison riot. Blackbeard also attacks the prison to do some recruiting, and the ultimate result is a mass jailbreak of at least 240 prisoners escaping, some Warlord-level, and some so dangerous that the Government had to erase their existence.
During the War, the Whitebeard Pirates and allies prove to be a powerful force, and decimate half of the Navy assembled forces. Whitebeard himself demolishes the Navy HQ, and splits the island in two. What's more, the arrival of the Red-Hair Pirates allows the surviving pirates to escape. Even worse, Blackbeard someone steals the power of the Tremor-Tremor Fruit, putting the most destructive Devil Fruit in the hands of a total madman.
After the War ends, Whitebeard's Famous Last Words confirm the existence of the One Piece, starting a second Great Age of Pirates, with the Navy being unable to respond properly because of their forces being decimated. Meanwhile, the power vacuum from his death has turned the New World into a bloodbath. Worse still, Fleet Admiral Sengoku and Vice-Admiral Garp choose to leave the Navy because of the Government's decisions, and following the promotion of Akainu / Sakazuki to Fleet Admiral, so does Aokiji / Kuzaan.
D.Gray-Man: At the end of the Noah's Ark Arc, after battling all these Noah, Allen Walker restores the Ark by playing a special song in a secret room within the Ark that the Noah don't know. Of course, Everyone who came along for the journey, got left behind, and supposedly died come back, but when they get back, poor Allen is charged for knowing how to control the Ark, since only certain Noah know how, and for being the container for the 14th. Not only does he have to control this monster inside his head, he has to be subjected to some not so good treatment from Leverrier. Now is that the way to treat your savior?
Twenty years before the main story in Mahou Sensei Negima!, Ala Rubra stopped the war in the Magical World and saved the world. Unfortunately, this was only achievable through the sealing of Asuna, which caused the floating capital to collapse and destroyed the cultural center of the world. The dynasty of the founders and kings of Ostia was also assumed to be wiped out when Arika was blamed for the disaster.
Arguably, the end of Code Geass goes something like this — Lelouch is dead, Suzaku's had to fake his death (and both of their reputations are in ruins), the entire populations of both Tokyo and the Britannian capital are dead and it's likely that Nunnally and several others are likely to need some kind of therapy. The world's at peace, but it's come at a heavy price.
In Great Teacher Onizuka a Pyrrhic Victory is achieved by an antagonist in a beauty pageant. By cheating the voting system, she manages to beat Tomoe in the pageant, but as she receives her reward, everyone in the audience boos her and claims to want Tomoe to be the winner.
Gurren Lagann: The Anti-Spirals are defeated, but more than half of the Gurren Brigade are dead, including Kittan, and Nia dies soon after returning to earth, because her life force was tied to the Anti-Spiral. On her wedding day of all days.
Puella Magi Madoka Magica: In any timeline (excepting the penultimate one) where Walpurgisnacht is defeated, all the local magical girls are left either dead or having expended so much magical power that they'll soon be powerful witches themselves.
This happens kind of a lot. Homura defeats Charlotte, but not before Mami dies. Sayaka prevents a witch from killing Madoka, Hitomi, and several adults by becoming a magical girl. This leads to her becoming a witch, and her destruction in a Heroic Sacrifice by Kyoko (yet another "victory").. In the ending, Madoka erases all witches from existence; but Sayaka and all the historical magical girls still die, and new witch-like monsters appear. Madoka herself disappears, and most people forget that she ever existed. Madoka seems pretty content with this outcome, though.
The resolution of the Yurin/Flit/Emily Love Triangle in Gundam AGE. Sure, Emily got to both marry Flit and be the mother of his children Asemu and Unoa, but this is because Yurin was horribly killed off, thus Emily's "second-best" for him. And she's very aware of it. And we're not counting how Flit himself was broken beyond belief by the death of Yurin... enough to become the Dark MessiahAnti-Hero.
By the end Nearly EVERYONE on both sides except the 3 main Gundam leads are dead. Although Flit was able to resist going genocidal on the Vegans in the end he'd more or less wasted his whole life on a cause he abandoned in the end, and he died shortly after the war ended. Asemu became a wanted criminal and missed out on his sons entire childhood, and he wasn't able to help Zeheart in the end. Kio got his peace he wanted, but all the Vegans he personally knew and wanted to save all died. In spite of this very bleak outlook the series acts like it was a super happy ending, one reason the ending was not well received by fans.
The conclusion of the First Space War in Super Dimension Fortress Macross. Yeah, humanity survived... by the skin of its teeth, with less than a million humans out of the six billion that once inhabited Earth, and the planet is devastated and barely hanging on as an ecosystem. As for the Zentraedi, with the destruction of the Main Fleet they no longer have the military power to oppose the Space Supervisionary Army, and many of them, in being absorbed into Earth culture, have lost their purpose in life, becoming little more than wandering bandits picking fights for no reason. Fortunately, it gets better.
There are a thousand or more Zentraedi main fleets in the galaxy, and the Supervision Army are just more Zentraedi when you get right down to it. It's less of there being no place to go back to as it is there being no way to get there, since the Zentraedi fleet that survived the battle is allied with the humans. Khamjin's entire plan, after destroying the Macross, is to go and find another Zentraedi fleet and get back to fighting.
Occurs in Stein's Gate when Rintaro finally returns from the alpha world line, where Mayuri is doomed to die somehow, to the beta world line, where Kurisu is doomed to be fatally stabbed. Subtly lampshaded when Rintaro then gives a huge, hammy speech proclaiming his victory, clearly on the verge of tears the whole time. Then subverted when it turns out that the beta world line must be averted in order to prevent World War III, and the way to do this is to go back in time again and save Kurisu, thus preventing an international time machine arms race and moving into a world line that Rintaro's future self dubs the "SteinsGate world line".
Tower of God basically hands Pyrrhic Victories out like candy — or, just murky ones where you wind up unsure if a clear "loss" or "gain" was ever possible in the first place. Every last win has a price (even the apparently clear ones), and many of them are steep to the point of only looking like a win on paper, particularly if you don't scrutinise either the build-up, the background shenanigans or the longer-term damage. It even manages to hand out the inverse, of course: Pyrrhic Losses happen to major or majorish characters where, although they technically or even practically lost, they won the mid-game or got a surprise gain related to their main goals from it, even if it wasn't the target they were specifically aiming at at the time.
In Attack on Titan, it seems that humanity is doomed to experience these. Any victory they manage to obtain by the skin of their teeth comes with heavy losses, and massive destruction, with the survivors wondering whether or not it could even be considered a true victory. Jean also questions whether any victory that requires them to throw away their humanity can even be considered a victory, rejecting the tendency of his superiors (and Armin) to fall back on stating that I Did What I Had to Do.
During the battle of Trost, humanity obtains their first victory. But with the city massively damaged, hundreds wounded or dead, and the gate forever sealed (undoing four years of the Survey Corps' hard work), no one feels like celebrating.
The raid on Stohess District ultimately succeeds in capturing Annie, thereby proving the existence of Titan Shifter spies and saving Eren from being handed over to the authorities. But with the city badly damaged, and the heavy toll on both civilian and military lives, many are horrified when Erwin states that it can be considered a victory. That Annie encased herself in a Crystal Prison to prevent interrogation does not help matters.
The mission to rescue Eren is successful, but at a massive physical and emotional cost. Erwin loses his right arm in the battle, and Hannes is among the many killed during the prolonged chase and battle. Krista is also successfully retrieved, but Ymir flees along with the exposed traitors — Reiner and Bertolt. That the group's surrogate Big Brother and Team Dad is The Mole is a devastating blow to everyone.
Toward the end of the Golden Age Arc in Berserk, the Band of the Hawk succeed in rescuing their leader Griffith from the torture dungeon in the Tower of Rebirth in Wyndham against all of the odds that were thrown at them (which included the king's guards, foreign assassins, and an exiled band of sadistic murdering and raping mercenaries led by a truly nasty Apostle). However, in the end, not much came out of it since Griffith was too physically damaged to be the leader or the man that he once was. Harsher in Hindsight though — despite how cruel it sounds, the Hawks were probably better off not rescuing Griffith if they knew what was going to happen to them.
In Yu-Gi-Oh! ZEXAL, when Kite defeats Mizar in a Duel. The cost? He dies from the cold vacuum of space afterward.
Sin City: All victories in this series are Pyrrhic and then some.
The Onslaught crossover invoked this trope by name in the last trade paperback that collected the series. Virtually every major hero within the main Marvel Universe is forced to sacrifice themselves in order to stop the main villain, Onslaught, by giving him a physical body. The mutants present at the fight, who were unable to sacrifice themselves in the above fashion, are forced to slaughter the heroes in order to destroy Onslaught once and for all, though much of the world ended up believing that they had simply killed off a huge crowd of beloved heroes.
Joker: You managed to find a way to win... and everybody still loses!!
Crisis on Infinite Earths: The heroes beat the Anti Monitor but in the process the entire multiverse is lost (and this is canon.) Arguably, the heroes can't be held responsible for the worlds lost before they got involved, but there were still six or seven worlds remaining when they began their counter offensive, two of them were destroyed and the other five were collapsed into one that was almost but not quite like one of the five with a few borrowed elements from the other four.
At least there are now 52 universes but none of them are the ones that were destroyed (though some are like the ones lost.)
The Long Halloween ends on this. Batman, Jim Gordon, and Harvey Dent form an alliance to take down Carmine Falcone just as Batman's familiar Rogues Gallery start to appear like The Joker, Scarecrow, Poison Ivy, and The Riddler. Falcone's empire is brought down—but the series ends with the Rogues Gallery in control and Harvey Dent has been transformed into Two-Face, with one of his first acts as Two-Face being killing Falcone himself.
Monica's Gang: Frankie gave his dog a bone and said dog spent most of the story trying to recover it from one adversity after another. By the time he got it back, he no longer had any teeth.
In the Total Drama fic Deserving, Courtney gets the million dollar briefcase, but the million dollars is used to pay her lawyers for the extravagances she included for herself when she re-entered the competition mid-season and all she's left with is $20. Not only that, but Duncan dumps her because she left him dangling off a cliff, hooking up with Gwen instead after she saved him. The final insult? She gets her head shaved by Heather!
Another Total Drama fanfiction example: King Nothing. Justin wins Total Drama Action and gets the million dollars. However, everyone hates him because he has revealed himself to be a manipulative, backstabbing liar — even his parents. Even after he graduates, he still can't get a job because no one will hire him, and finally turns to a drinking habit. Eventually he runs out of money and the last we see of him is working as a janitor at some crappy bar, and having lost his good looks from his alcoholic habit.
A Brief History of Equestria: The conclusion of the Celestine Civil War: Sullamander is overthrown and the balance of power in the river valley is maintained, but Wind Whistler is killed, Celestine itself lies largely in ruins, a large chunk of the population view Hurricane and the rebels as traitors unfit to rule, and Lake Trot, the objective which instigated the war, freezes over, rendering all the death and destruction pointless.
In The Conversion Bureau Not Alone, this is the end result of the war for humanity and Earth, combined with a Bittersweet Ending. Although humanity wins the war against Equestria's Assimilation Plot, forcing them to retreat, several soldiers have been killed in the war. Not only that, but South Africa (which has suffered a staggering loss of infrastructure thanks to the barrier wiping it out) is rapidly turning into a fascist hellhole, and several countries, running on paranoia due to humanity's first encounter with an alien species being an Alien Invasion with the intention of xenocide, have started to spend massive amounts of money (at the cost of education and healthcare) on beefing up their military forces and preparing for a war that will never happen.
The Alternate Ending of The Lion King was one of these for Scar. He beats Simba and throws him off Pride Rock but unknowingly saved Simba's life in the process, as the fires engulf Pride Rock, killing Scar. All Scar's 'victory' did was result in killing himself and allowing Simba to become king. At that point, however, he probably didn't care, seeing how he was also laughing as he was burning up.
In Wreck-It Ralph, Ralph gets the medal he wanted and returns to his own game, after destroying Vanellope's racecar to prevent her from racing. There finds out that Fix-It Felix has left trying to find him and has yet to return, and their game is about to be unplugged. So, Ralph's won a medal, broke a little girl's heart, and has the key to a Penthouse suite he was told he'd never get in a game about to be unplugged...Nice Job Wrecking It, Ralph. Though he DOES set everything right in the end.
Pretty much every time the good guys win something at ANY point in The Dark Knight it comes at HUGE cost. Might even be the movie's main theme.
By the end of the film Harvey Dent has gone insane and started murdering people, has gotten killed and Batman has taken the heat for the murdersall so the Joker won't win. And then Bane completely makes the victory useless when he reveals Dent's crimes in the next movie.
Transformers' ending had Megatron defeated, but at the cost of the Allspark, which means the aliens' home planet Cybertron can never be restored.
DOTM's ending had all the major Decepticons killed off, and the Autobots managed to save humanity from enslavement at the hands of the Decepticons. Cost? Only eight Autobots are confirmed to survive the trilogy. Chicago's in ruins and the Autobots' Hero Insurance are rather lukewarm in this series. Cybertron was also implied to be destroyed, making it pretty impossible for any Transformer to return home, let alone restore it. (The upcoming sequel may prove otherwise).
L.A. Confidential: Ed Exley has to destroy pretty much everything he cares about over the course of the movie.
Even moreso in the book. By the time White Jazz rolls around, Exley is effectively cut off from every other character, using them as pawns to achieve his own ends.
In Ginger Snaps, Bridget manages to escape being eaten by the werewolf by accidentally killing it. And it's her sister, the only person in the world she loved, and who she'd hoped to cure.
An implication of The Descent was that this was the only way the characters could beat the monsters and escape was to become equally as savage and primal, which was the main character arc for the lead. Although in the end she subverts it when—after about twenty minutes of being progressively Ax-Crazy—she sees her dead daughter, and chooses to stay with the hallucination rather than keep fighting.
Set It Off. The protagonist escapes with a fortune stolen from a bank but her friends were killed, she had to leave the man she loved behind and she can never return to the United States.
Blade Runner. Director's cut ending. Deckard runs away with Rachel, a Replicant, a very illegal act, despite her having less than four years to live.
Similarly, The Search for Spock ends with Spock revived and the Klingons defeated, but at the cost of Kirk's son David Marcus, the Genesis planet, and the original Enterprise.
Clonus ends with Clonus being exposed and Senator Knight's political career ruined. However, anyone who tried to help Richard is now dead, Lena is lobotomized and Richard's own heart now beats in the body of Sen. Knight's brother (who Richard was cloned from) For added downer effect, we learn that Walker's first name is George.
Mallrats: the Stinkpalm, a practical joke which involves sticking one's hand between one's own buttocks before shaking hands with the prankee.
T.S.: What's the point?
Brodie: You know how long it takes for that smell to come off? Scrub all you want, it'll stick around for at least two days. How does he explain it to his colleagues and family? They'll think he doesn't know how to wipe his ass properly.
T.S.: Meanwhile you yourself are left with a hand that smells like shit.
Brodie: Small price to pay for the smiting of one's enemies.
Cloverfield: The monster is (probably) defeated, but every single main cast member (except one, and she may well actually be dead too) is dead, along with most of the population of New York City, and the city has been destroyed.
Clover is a baby and if the mother finds the dead body or goes looking for it...
For most of The Book of Eli, the Big Bad chases Denzel Washington's character across the wasteland, trying to obtain the book. He finally gets it in the end, but loses so many men that he can no longer rule over his people. Also, his wound is infected, which is usually a death sentence. To top it off, the book is in Braille, and the only person who could possibly read it just lost the fear that had kept her obedient and subservient.
In Bullitt, Lt. Bullitt succeeds in finding all the people responsible for the death of a man under Witness Protection. All of these criminals end up dead, thus ruining the larger goal of acquiring testimony to bring down The Mafia.
The Pledge is an interesting case, where the main character doesn't even realize he's won a Pyrrhic victory. He used a little girl as bait in an unsuccessful attempt to draw in a serial killer. The child's mother finds out and hates him for it. His former colleagues lose all respect for him. He ends up alone in a pit of guilt and self-pity. But it turns out the plan would have been successful, if the killer hadn't died in an accident before he could be caught.
In One Eight Seven, Rita invokes the trope name when talking about the Trevor Garfield (Samuel L. Jackson) in her commencement speech after Garfield's war with the K.O.S. gang leaves the key players dead, including Garfield.
The John Cusack Western The Jack Bull is about a horse trader, Myrl Redding, who goes to great lengths to ensure the prosecution of a rancher who screwed him over in a deal. He succeeds, but only after exhaustively tracking the rancher and declaring war on anyone who harbors or sympathizes with him. The trail of collateral damage Myrl leaves in his wake includes two people dead: the first killed accidentally by someone else and the second killed by Myrl in self-defense. Myrl's trial is conducted immediately after that of the rancher, who is sentenced to a month of labor in Myrl's stable. The judge accepts Myrl's claim of self-defense in relation to the second killing, but is compelled by the evidence to find him guilty of murder in relation to the first, even though he believes Myrl probably didn't do it, and sentences him to hang.
Invoked in Shakma. A sort-of LARP, where characters have to solve puzzles to win the game, is crashed by a killer baboon (the eponymous Shakma). In the end, the sole surviving character, exhausted by his wounds, lays on the ground and finds it darkly humorous that he "won".
Real Steel. Zeus wins his fight against Atom. But only by being saved by the bell. The crowd reaction makes it clear that his "Victory" has cost him and his creator a severe and possibly unfixable blow to their reputations.
As Jon Snow wins battles and climbs up the rank of the Night's Watch, he loses the respect of his black brothers.
The Battle of the Blackwater is another excellent example. This is something of a hallmark of the series. A non-Pyrrhic victor tends to be an Unwitting Pawn, up to and including some of the competing Chessmasters.
Robb Stark's situation for close to three books. His Northern army curb stomps the Lannisters in his first major battle, putting him well on his way to winning the war in short order. However, other circumstances come into play, and while he is never beaten on the field, with every "victory" his situation becomes more and more precarious as the North stands alone while Tywin Lannister forms alliances with the other ruling families against him.
The Lannister victory in the War of Five Kings. Yes, they won the Iron Throne, but in the process virtually every important member of the family was killed, exiled, or maimed.
Jaime: I’ve lost a hand, a father, a son, a sister, and a lover, and soon enough I will lose a brother. And yet they keep telling me House Lannister has won this war.
Robert's Rebellion in the backstory, especially if you're Robert. His entire motivation was to rescue his beloved, Lyanna Stark, from the Targaryens. She died before he could do so. He ended up with the throne but not the girl (and with a loveless marriage).
Daenerys's sacking of Slaver's Bay. Despite having the strength to crush three cities, she leaves a power vacuum in Yunkai and Astapor since her supporters are vastly outnumbered by her enemies. In Meereen, all of her attempts to reform the city are met with resistance and Dany ends up fleeing the city on her dragon's back after a failed assassination attempt.
House Frey's betrayal of the Starks wins them the favour of the Lannisters and the Iron Throne, but also the enmity of just about everyone else and the total ruin of their reputation. More Freys die in retaliation for the Red Wedding than in the War of the Five Kings.
Gregor Clegane managed to win a duel against a Dornish Prince only to spend the succeeding weeks dying in screaming pain from the poison used by his opponent. If he'd managed to pull through, his employers planned to cut off his head and send it to Dorne with their apologies.
The Siege of Dragonstone in AFFC. Queen Cersei was informed by the Grand Admiral(who eventually betrayed her) that while they managed to take the stronghold, the casualties from the assault is described as an unnecessary bloodbath note approximately 1000 dead consististing of mostly young lords and knights in contrast to the token force on Dragonstone and an able knight grievously wounded. Later the small council tries to recoup their losses by ordering a search of the castle for any wealth, which ends in vain. All in all the Iron throne paid a heavy price for an island which Stannis note The previous occupant of Dragonstone called a godforsaken rock.
The Dance of the Dragons ended with Aegon II victorious but so severely burned that he only has a year to live, all his heirs are dead so the crown will eventually pass to his nephew who is the son of his arch enemy and all the Targaryen dragons are dead.
R.A Salvatore's The Crystal Shard has the final battle presented as one of these for the good guys.
The Thousand Orcs has another. The last of the survivors of the attack on the town are spirited away by means involving a fake idol of Gruumsh, the orc god. When the other orc shamans hear about this, they not only bring in thousands of new recruits to avenge the sacrilege, they also perform a rare ritual on the orc king that makes him permanently stronger and quicker.
In World War Z humanity managed to be victorious over the zombie hordes. But the war and overall situation devastated the planet.
In A Darkness at Sethanon, the invading army of the moredhel finally captures the city of Armengar, but with devastating losses—not only is the city an invader's nightmare, built with technologies and magic long lost to mankind, but those in charge of the defense blow it up just when the invading army has finally broken through, leaving the moredhel with a ruined city and great losses. Ten years later, the risk of a devastating defeat or a Pyrrhic Victory is what spurs one of the moredhel chieftains to oppose the efforts to launch another invasion, going as far as allying himself with the humans to accomplish it.
In Dan Abnett's Warhammer 40,000 novel Brothers of the Snake, a chapter of Space Marines retake a refinery from Chaos forces. They realize that the place was tainted by something it had pumped up from under the earth, and it could not be used any more — which meant they could just have blasted it from orbit, without losing three Marines in the fight.
In a similar vein, the defense of Vervunhive, which leaves the hive with so many dead it is officially decommissioned at the end of the war. Although with Heritor Asphodel dead, Chaos has nothing to celebrate, either.
Ciaphas Cain, in Caves of Ice, digs his troops in to protect a Promethium refinery that he later has to annihilate to stop a Necron tomb from reawakening. (Still, taking out an Ork Waaagh and a Necron force is a solid deal for one refinery, especially since they managed to evacuate the facility beforehand.)
The final book of the Ultramarines series has a surprisingly major one. The Ultramarines successfully beat back a massive force of traitor marines and permanently kill a daemon prince, an act practically unheard of in the universe, but Ultramar itself has lost several worlds and almost four companies worth of marines.
Animorphs ends with a cliffhander implying the deaths of all but one of the surviving protagonists. While worth it for the free fate of earth (at least temporarily), almost all of the children who survived until the end of the war were emotionally broken beyond repair from their trauma and the things they were forced to do.
The third Malazan Book of the Fallen book, Memories of Ice, has two. First the siege of Capustan is lifted when the protagonist army arrives, but the defenders (who are honorable mercenaries) have nearly been killed to the man. This trope is used again in the concluding battle where the protagonist army captures Pale. But a huge percentage of the named protagonists are killed during this second battle and the army is a shell of it's former self.
Lampshaded in The Lord of the Rings: "Today we may make the enemy pay ten times our loss at the passage and yet [we may] rue the exchange. For he can afford to lose a host better than we to lose a company."
In fact, Pyrrhic victories are quite common throughout Middle-Earth's history. The War of Wrath ended with Morgoth's defeat, but all of Beleriand was laid waste in the battle and sank under the sea. The Last Alliance managed to defeat Sauron, but lost so many people that the kingdoms of Elves and Men ended up depopulated and ripe for attack by Sauron's human allies, which led to the destruction of Arnor and the reduction of the Elves to just a few small settlements. Even the final victory over Sauron in The Lord of the Rings was Pyrrhic, in that destroying the Ring led to the final waning of 'magic' in Middle-Earth and the departure of the remaining Elves to the West.
The other two Battles of Beleriand against Morgoth (that the Elves actually won) were Pyrrhic as well. The first ended with one faction of Elves demoralized so badly they essentially demilitarized and took to a "stay hidden" policy against Morgoth since the bloodline of their leaders was killed off, while the second ended with the death of Fëanor, greatest of all the Elves. Sure it was still a crushing victory for the Elves short-term, and he was a right bastard to be sure, but one can only imagine what he would have done for the war effort (not to mention morale) had he lived.
Lampshaded in The Lies of Locke Lamora. Locke and Jean kill their enemies, but they have to leave Camorr forever, they're both injured (Locke especially so), and all their friends are, by the way, dead. The exchange goes something like:
Locke: So this is winning.
Jean: It is.
Locke: It can go fuck itself.
The Dresden Files has several such victories, most notably in Turn Coat. Morgan is dead, the (only identified) traitor in the council is dead, Dresden and McCoy have no further information on the Black Council, the White Council has lost three of its most valuable members (the man Morgan was framed for murdering, Morgan, and the traitor), virtually everyone within the council needs to go in for deprogramming from mind-control magics, the Senior Council is now living in a permanent state of wondering if their actions were truly their own, and their newest member may or may not be a member of the Black Council.
Also, Grave Peril. Dresden got the girl back, but couldn't save her. And in the process, started a war.
Changes So Harry won the war, wiped out the entire Red Court, and saved his daughter. He only had to murder his daughter's mother and become Mab's servant. And as Ghost Story shows, destroying the Red Court only led to an Evil Power Vacuum and even worse forces moving in.
Described as an inevitability in Sergey Lukyanenko's novel Genome in a war between two galactic powers with relatively equal military strength. A historical example is cited with the ancient Taii Empire, whose territory once spanned much of what is now owned by the younger races. They engaged in an all-out war with another empire, resulting in a Taii military victory but at the cost of utter devastation of their empire. The Taii briefly described in the book are now a dying power, holding no more then several dozen worlds and flying enormous ships that are ridiculously inferior when compared with more modern ships of the younger races. The same fate is predicted for the humans or the Czygu in a total Bug War. This prospect would force the humans to recruit the aid of a colony of Church Militants whose goal is the total extermination of all aliens for the betterment of the "true children of God." This would cause all other alien races to ally against humanity, resulting in this for everyone who survives.
Ender’s Game has Ender defeat the Buggers, only he ends up doing so by wiping them out entirely when they were revealed to have attacked only before they realized humans were sentient, and he gets exiled from Earth as well (not to mention how every human ship involved in the battle is destroyed either by Bugger Defenders or the M.D. Device)
In the Farsala Trilogy by Hilari Bell, the Roman Empire Expy have many rules about their conquering of other territories and one of those rules is that if they don't have full control of the country within a year then they will withdraw their forces and offer allegiance with it instead or just leave it alone. This rule was put in place because early in their history, they were victors of this and vowed that victory would never cost so high again. According to the books, they're so good at taking over countries that out of the dozens they'd taken over only two were been able to resist past the time limit.
In the Percy Jackson series, Kronos, the Titan Lord, is called 'the Crooked One' for his ability to engineer schemes which leaves the good guys in a tight spot either way. It is possible to foil him, but it almost never happens without cost, often a heavy one.
The third book is a good example of this. They finished their quest, saved Artemis and stopped the baddies from harnessing the powers of a world-destroying beast...but two of their teammates died in the process, and the younger brother of the second one is not happy. It got worse when Percy realized that not only did he have another demigod bent on killing him, but said demigod was a son of Hades, which qualified him in the prophecy that could destroy Olympus and all of Western civilization. Ouch.
In Starship Troopers, it's pointed out early on in the war that killing 1,000 bugs for each human is a net victory for the bugs, as their soldiers can be hatched at need and can be ready to fight in a matter of weeks, while it takes the better part of a year to make a Cap Trooper battle-ready.
In Arena, a short story by Fredric Brown, an energy being, right before the first major battle between humans and aliens, states that they cannot coexist peacefully, and a war between the two will end in one extinction and one stone age. Since both races had the potential to evolve to the energy-being's level, unless their civilization was ruined by this war, the energy being snatched up both a human and an alien Roller and pit them against each other in a one-on-one duel with the complete and instant annihilation of the enemy's battle fleet up as the stakes specifically to avert this outcome.
The backstory to the Wheel of Time series has the triumph of the Light and the sealing of the Dark One in the Age of Legends made out to be one of these for all concerned. The backlash of the sealing left a taint on the male half of the One Power that doomed every man who touched the Power to creeping insanity and death, without exception; this left a bunch of completely insane men with the power to level cities and raise mountains running around causing almost as much damage as the war that they ended would have, destroying so much that the knowledge and culture of the Age of Legends was in large part lost forever. And for Lews Therin, the hero who led the charge to seal the Dark One? His nemesis tracks him down at his mansion and uses a Dark version of Healing to cure his madness, allowing Lews Therin to see that, while insane, he had murdered everyone and everything he had ever loved. He did not take it well.
Time Scout: Congratulations, Skeeter! You just stood up to a bully! A bully with massive wealth, criminal connections, government power, and a vindictive nature. And you've a checkered past he won't have any trouble using against you.
In The Hunger Games, winning the Games is depicted as such. Because There Are No Therapists, survivors of the arena walk out with wealth and fame for life, but with severe PTSD and nothing to help them cope with their experiences — and they have to mentor the tributes for the following Hunger Games, until they die. For example, Haymitch, the mentor to Katniss, has spent twenty-four year trying to mentor children and bringing home corpses. The trope is Invoked in this case — the Capitol doesn't want the Victors to be able to lead a coup.
Katniss' mental breakdown in Mockingjay. Even though the Capitol fell, Prim's death takes precedence.
In one of The History of the Galaxy novels, the first battlefield use of the LIGHT annihilator device by La Résistance results in the total destruction of not one but two Earth Alliance armadas. However, the colonists lose nearly all ships in the process, leaving them with a total of eight warships, while Earth still has plenty of ships in other systems. They also lose the only existing annihilator they have (at the moment). Their only advantage is the fact that Earth has no idea the colonies are virtually defenseless. The new colonial admiral manages to enact a daring plan to steal two flagship-class cruisers from an Alliance shipyard... by stealing the shipyard with tugs.
Oh, and the admiral's own son was killed in the explosion.
In Dickens' Bleak House, one of the major plot points of the book is the infamous legal case Jarndyce v. Jarndyce. Near the end of the book, the characters finally win the case, but the cost and time—several years, and the modern equivalent of hundreds of thousands of dollars—that had to be invested in trying to untangle its legal Mind Screw rendered it bankrupt by the time they finally finished. It ate up all its own assets, which would have been worth a fortune if it had been some halfway competent lawyers who drew up the mess in the first place.
Yes, at the end of the Star Trek: Destiny series the Borg are eliminated as a threat once and for all. It only cost 63 billion lives, dozens if not hundreds of inhabited planets throughout the Alpha Quadrant, the destruction of almost half of Starfleet, and significant casualties among all of the other major powers of the Alpha and Beta Quadrants. President Bacco states that the toll essentially sets the Federation back almost a century.
The Mirrorworld Series: Sure, Jacob ultimately accomplishes what he set out to do, but then there are all those people who end up dead...
In The Lost Fleet, the 100 years war between The Alliance and the Syndicate Worlds is chock full of such battles. Any victory is won with huge casualties. This is in large part due to both sides forgetting complex fleet tactics and switches to an Attack! Attack! Attack! mentality, where each ship individually charges into battle and hopes to win through sheer "fighting spirit". Battleships are considered to be posts for cowards, as they have too much armor and shields and can't get to the battle fast enough. Then Captain John "Black Jack" Geary is discovered as a Human Popsicle and revived and uses his knowledge of fleet tactics to win without this trope.
"You may win this war, Commander, but I promise you, by the time it's over, you will have lost so many ships, so many lives, that your 'victory' will taste as bitter as defeat."
Discussed in the two-part special "The Way of the Warrior", when the battle between Deep Space Nine and a Klingon attack force reaches a stalemate.
Worf: "Consider what you do here today, Gowron! Kahless himself said, 'Destroying an empire to win a battle is no victory '! "
Gowron: "'And ending a battle to save an empire is no defeat'."
In the opening battle of the Dominion War, Dukat managed to capture Deep Space 9, but lost over 50 ships, a vital shipyard, and failed to bring in reinforcements through the wormhole. Nevertheless, that didn't stop him...
In The Shield's series finale Vic Mackey succeeded in getting away with everything he's done, but no friends in the world, his family relocated out of fear from him, and his new employment is guaranteed to be Hell for the next three years. So yes, he won, but the cost was obscene.
During the evacuation of New Caprica in Battlestar Galactica, the Galactica and most of the civilian ships manage to escape the planet...at the cost of massive damage to Galactica and the loss of the high-tech, advanced battlestar Pegasus, which was capable of building Vipers. Nice job breaking it, Lee.
In the third season, Londo collaborates with G'Kar to assassinate the villainous Lord Refa, which ultimately removes the only moderating influence on an even worse leader, the insane Emperor Cartagia.
And then in the fourth season, Londo and Vir kill off Cartagia and Morden and blow up all the Shadow ships stationed on Centauri Prime, finally freeing the planet from the Shadows' influence... only to cause the Drahk to take over the place in revenge in the final season, leading to Centauri Prime's isolation from the rest of the galaxy, the firebombing of its cities, and just general devastation of the whole planet. And not only does Londo have to watch all this unfold, but he also gets possessed by a Body Snatcher — and he has to live with all this for the rest of his life. Brr.....
Londo could very well be the Trope Codifier. This is in fact the whole point of his arc—his association with Morden and the Shadows gives him everything he says he wants, but each time at a terrible cost—bringing into sharper focusthe Shadow question, "What do you want?". The DVD commentaries point this out, but really, it's plain for all to see.
To give that line some context, at the end of "Last of the Time Lords" the Master gets shot by Lucy Saxon after the Doctor's ended his regime over the Earth. Rather than regenerate (and subsequently spend the rest of his life imprisoned on the Doctor's TARDIS) he chooses to die, leaving the Doctor alone as the only living Time Lord once again. It's a pyrrhic victory for them both.
However, the Master pulls a Thanatos Gambit by anticipating his death and getting his cult to resurrect him a year later. But he's not the only one. Lucy Saxon has also made arrangements to prevent this and ends up making a Heroic Sacrifice to prevent her husband's resurrection; he ends up Coming Back Wrong.
And more recently, the Doctor's victory in "The Waters of Mars." He saved the remaining crew but changed history in the process, believing that the rules of Time will bend to his will. Adelaide realizes how wrong the turn of events is and subsequently kills herself in order to correct the timeline.
The only thing her suicide did was cause the Doctor to realize how wrong he'd been, thinking that he's untouchable. The timeline was already altered, as the survivors revealed what happened to the authorities; in the original timeline, the events on Mars remained a mystery.
At the end of the Torchwood miniseries Children of Earth, Jack manages to save the world. However, in order to do so, he had to kill his grandson. Not to mention that his boyfriend also just died in the previous episode...
In Power Rangers RPM, in the Grand Finale, after three long years the rangers win the Robot War... but by the time the Big Bad goes down, at least 90% of humanity is dead, with the entire planet outside of Corinth's protective dome having been bombed to a post-nuclear war wasteland. Plants are just starting to regrow in the less radioactively "hot" areas, but the global ecosystem is by and large too far gone to recover most of the lost biodiversity or return with new life with any speed.
Sylar finds this out the hard way in Volume 5 of Heroes. He's got everything he ever wanted. He's the most powerful Evolved Human on the face of the earth. He's immortal and invulnerable to harm. There's maybe a gran total of two people (That we know of) who could realistically pose a threat to him and he can easily take all the powers he wants. He's also killed the only two people who ever cared for him and realises that he's now going to be utterly alone, wretched and despised for eternity. It's enough to mke him have yet another Heel-Face Turn this one seemingly more permanent than the previous ones.
In the series finale of Angel the main cast has successfully set back Wolfram and Hart's plans for the apocalypse by at least several years. The cost is the loss of their control over the firm's earthly assets, the death of two major characters, abandonment of a third, severe wounding of a fourth, and a textbook Bolivian Army Ending. And despite all of that, they decide to make their end memorable.
24 excels at these, but Day 3 is particularly notable for how Jack Bauer, Tony Almeida and Gael Ortega set in motion a plan to destroy the Cordella virus. The day ends with Gael having died horribly of the disease, Tony being shot and watching the scheme nearly kill his wife and facing 20 years in federal prison, and Jack breaking down crying in his car. But hey... they do accomplish what they set out to do, which is contain the virus.
At the end of season 7, the Sangalan rebels are defeated, the nerve gas is captured, and the head of a wider conspiracy is finally caught. The cost, a) the President lost her son, and almost lost her daughter and husband, b) a loyal FBI agent loses her boss and close confidant, and it is implied, her sanity, c) the White House is shot up to shit, d) a man who was royally screwed by a previous Presidential administration sacrifices his life to save the White House staff, e) one of Jack's most trusted allies turns on him and f) Jack nearly dies an agonizing and undignified death.
This trope is taken Up to Eleven in the eighth and final season. The IRK terrorists, as well Charles Logan, Yuri Suvarov and their minions are stopped, but at an enormously high cost. President Omar Hassan sacrifices himself and lets the terrorists kill him to save New York from a dirty bomb. Renee Walker, after further losing her sanity, is killed after finally making love with Jack. Jack snaps after her death and unleashes hell on all the conspirators in Renee's death, as well as all the CTU people trying to stop him, to the point where he has to flee the country because both the US and Russian governments are hunting him. Thus, he must once again abandon his friends and family. Chloe is arrested and facing at least 15 years in prison for helping Jack escape, leaving her family behind as well (and by extension, Cole and Arlo may be facing similar charges, considering their role in helping Chloe). Finally, President Taylor has crossed so many lines trying to save a treaty that was ridiculous from the very beginning and covering up the Russians' involvement in the terrorist activities, and she is very aware of it. Though she confesses everything at the every end, she will likely be facing impeachment or worse. Combined with essentially the loss of her entire family, her life is a wreck indeed. It is safe to say that nobody in this series is going to have a very happy ending. Perhaps The Movie of 24 can fix this... but that doesn't seem very likely...
Season 7 has Sam and Dean successfully kill the Leviathans and save humanity from a future of being mindless cattle, but Dean and Castiel are sent to Purgatory in the ensuing blast, Meg and Kevin are captured by Crowley's demons, and Bobby by then has passed on. So basically Sam is alone with Crowley in control of the power vacuum caused by the Leviathans.
The eponymous team of Stargate SG-1 is accusedof this from time to time in the show. In one episode they're bragging that they've done more in the last few years to defeat the Goa'uld than other groups have managed to do in centuries. The ally they're talking to points out that all they've really done is create power vacuums among the System Lords that have almost inevitably resulted in even worse individuals attaining power. Since Jack is usually the one this is directed at, his response amounts to "at least we're trying."
The Chinese Paladin (Xian Jian Qi Xia Zhuan) TV Series definitely qualifies here, as the main character, Li Xiaoyao, literally loses everyone dear to himself except his newborn daughter a couple scenes right after the "final battle."
Played for laughs in Friends when Chandler got the highest score in Ms. Pac-Man but his hand became spasmed and stuck in a "claw" formation.
I got the highest score, but at a price.
The Battle of Witchhead in Andromeda turned into this for the Nietzscheans, although they arrived to the battle preparing to ambush a fleet of 100 High Guard ships with an armada of 1500, which would've been a Curb-Stomp Battle. Then Hunt (AKA the Angel of Death) shows up and wipes out 1000 ships, damaging the rest, and sewing disarray among the Nietzchean ranks. The High Guard fleet shows up shortly after and is still wiped out, but the Neitzscheans are left with hardly anything themselves. In fact, the ruling Drago-Kazov Pride was supposed to form the dynasty for the new Nietzschean Empire, but their losses mean that they no longer have the power to unite the warring prides, resulting in a 300-year power vacuum.
Interestingly, the pride that turned on the Drago-Kazov and prevented them from forming an empire ends up allying with Hunt 300 years later, as they have been mortal enemies with the Drago-Kazov since then.
In How I Met Your Mother, Marshall was able to win a lawsuit against a pharmaceutical company but the judge was unwilling to hurt the company by fining them with the intended 25 million dollars and so, reduced it to 25 thousand (0.1% of the original). Marshall was very upset since more was probably spent on court fees and lawyer paychecks for each side. This event would inspire him to apply to be a judge so he would have more influence on the system. An earlier episode revealed that Marshall's law firm kept itself afloat by settling all their cases and avoiding fighting any cases where they could experience one. Marshall inspired them to contest cases in court again which resulted in his case ending up as one. By the end of the season the law firm is broke and has laid off almost all employees.
Ted experiences this when he ensured that Robin would go after Barney at the expense of leaving him alone at the opening of the building he designed. The last scene is him looking out a window depressed while the rest of the gang was happy.
In Revolution the rebellion led by Miles Matheson is winning victories against the Monroe Republic but for Miles every such victory is pyrrhic. Every fighter he loses is someone he cannot replace and the enemies he is killing are old friends and protegees of his. Even if he removes Monroe from power, the Republic will be finished and it will become part of the Georgia Federation.
Occasionally happens on Top Gear with their races or challenges.
The four-way race across London during rush-hour traffic between a bike, a car, public transportation and a motorboat down the Thames. Hammond, riding the bike, won, but he spent the entire episode cursing out traffic lights and almost getting hit by buses. He was also visibly exhausted by the end. Jeremy came in second on the boat, but he had by far the most relaxing and least stressful journey. What sealed the deal was that James came dead last in the car, which lead to everyone joking that Top Gear (a show all about cars) was Ruined Forever.
This was, according to medieval myth, the fate of anyone who stabbed a basilisk. Lucian described it thusly: "What though the Moor the Basilisk hath slain, and pinned him lifeless to the sandy plain, up through the spear the subtle venom flies; the hand imbibes it, and the victor dies."
In the American folk tale/folk song of "John Henry," the eponymous character ends up competing against a machine in regards to who can drill rock for a railroad tunnel faster. John Henry manages to win against the machine, but the competition ultimately cost him his life as a result of overworking himself.
The Undertaker suffered one during his WrestleMania 27 match with Triple H. Though Taker won the match, moving his WrestleMania undefeated streak to 19-0, he was so worn out afterwards that he couldn't even stand up to do his darkness salute. Taker had to be taken out on a stretcher while Triple H, the loser, was at least able to walk to the back under his own power.
The Thran race "won" the Thran-Phyrexian war, but their civilization had been damaged too greatly to recover, and soon collapsed.
Urza and company then won the second Phyrexian war, but at the cost of the lives of pretty much every named character, leaving behind an incredibly powerful artifact which started the next big war on Dominaria, whose conclusion left Dominaria in a state that very nearly tore the multiverse to shreds.
This later led to the conflict on Mirrodin, both of which were caused by the phyrexian oil. The first one was won, but at the cost of basically depopulating the plane. The second one didn't go much better.
Something tells me the Phyrexians were named that way for a reason.
This flavor text for the card Obliterate. Fitting.
"The enemy has been destroyed, sir. So have the forest, the city, your palace, your dog..." —Keldon soldier
Meet the mission's objectives in a game of Warhammer 40,000 and you win, even if doing so cost your Space Marines their Chapter Master and dozens of their greatest warriors. The fluff has even more examples:
The original Pyrrhic Victory would be the Imperium's triumph over Chaos during the Horus Heresy. The renegade Warmaster was defeated, but the Emperor was mortally wounded and placed on life support, leaving him incommunicado for the ten thousand years since. His Imperium, founded on humanism and atheistic science, degenerates into a totalitarian theocracy where he is worshiped as a god while the local "engineers" worship their tanks. Humanity is so weakened by the conflict that civilization has never recovered to its heights at the Imperium's founding. And if the Emperor had been given just a little more time to perfect his Warp Gate, he could've revolutionized galactic transportation so that it wouldn't rely on Warp travel and mutant Navigators.
Earlier than that, the Eldar god of war, Kaela Mensha Khaine, managed to defeat the Nightbringer during the near-mythical War in Heaven, but Khaine was nearly killed and the battle gave all sentient life an intrinsic fear of death (all sentient life except the Orks, anyway). On the other hand, when Khaine battled Slaanesh during the Fall of the Eldar, even through his defeat he managed to weaken the Chaos God enough for Cegorach to escape and Nurgle to "rescue" Isha.
Most victories against the Tyranids. It takes a staggering amount of manpower and war material to stop a Hive Fleet, and there's always another one lurking in the void. The 'Nids even use this on the battlefield, forcing their enemy to waste ammunition on swarms of Cannon Fodder before launching the attack proper. The more extreme method of using Exterminatus on worlds under Tyranid attack is a two-way Pyrrhic Victory. The Tyranids lose both the potential bio-mass of the planet they were trying to eat as well as that of the forces spent attacking it, but at the same time the Imperium has just sacrificed one of their finite and ever-shrinking number of planets, while the Tyranids seem endless.
Specific examples of this would be the Battle of Macragge note where the Ultramarines stopped the rampage of Hive Fleet Behemoth at the cost of billions of lives, hundreds of worlds, and the sacrifice of the elite Ultramarines 1st Company and the Battle of Iyanden note where, with the help of Prince Yriel and his Eldritch Raiders, the Eldar were able to overcome Hive Fleet Kraken at the cost of four-fifths of the Craftworld's population, and Prince Yriel had to take up the Spear of Twilight which will inevitably slowly kill him.
Eldrad's destruction of Abaddon's Planet Killer broke the back of the Thirteenth Black Crusade, but the Farseer locked himself in eternal conflict with the daemonic spirits controlling the warship and was hurled into the depths of the Warp.
On a meta level, world-wide "you determine the result" campaigns fall into this, since having one side flat-out lose would irritate players. So while global campaigns have ended in Imperial (specifically Space Marine) victories, reading deeper reveals that their enemies made off with some powerful artifact or achieved their true objectives. As an example, the Dark Eldar were defeated in the Medusa campaign, but snatched so many slaves that they'll be able to gorge themselves for eons.
Mage: The Ascension: The Technocracy has all but won the Ascension War... and in the process created a humanity that has no interest in Ascending.
Ravenloft, for both heroes and villains. The heroes won't be able to achieve particularly significant things, and it's quite likely they will die in the process of saving a handful; on the Darklords' side of the ledger...well...Count Strahd saved his homeland at the expense of his youth and became immortal at the expense of the life of the woman he loved, to name just one example.
Risk - Throw fifteen troops into an invasion, end up with one left to occupy the territory against the might of the entire enemy continent.
Blood Bowl: Congratulations, your skaven just beat the enemy orc team 2-1! You won 60,000 gold pieces... And your 80,000 gold piece stormvermin was killed and one of your 70,000 gutter runners got his neck broken, to say nothing of all the linerats they chewed through first. Only another... Five matches until you've replaced your losses.
Necromunda, in a similar vein to Blood Bowl above, can have the winning gang achieve rather hollow victories over the enemy, especially if they suffered a lot of casualties on the playfield. Worse, the losing player may actually roll results on the injury table that are actually beneficial to their team, so assuming they get some lucky rolls and you get some bad ones, you may end up with a horribly mutilated winning gang with several dead or permanently injured gang members while the defeated gang may end up objectively stronger as a result.
Hamlet manages to avenge his father, but nearly every major character dies as a direct or indirect consequence. Lampshaded when he asks an actor to recite a speech about Pyrrhus, albeit the Homeric Pyrrhus and not the trope namer.
An Irish play called The Field has a farmer trying desperately to get a plot of land from the woman who owns it. The reason? He wants to pass on something to his son. Of course, the farmer goes to such awful lengths to get the land (including killing someone), that by the time he finally does get the land, it's worthless to him.
Wicked: Both Elphaba and Glinda have these. The former has survived her death sentence, but must pretend to be dead, grievously hurting her best friend, and accept voluntary banishment. Glinda, said best friend, has ascended as the effective ruler of Oz, but at the cost of the lives of her friends and fiancé.
In Vol. 3 the answer for one of the Impossible Questions was 'Pyrrhic victory'. However, if you got it right the game took points off you anyway. Oh how we laughed.
Episode 9 of the 2011 release had a question about the definition of a "pyrrhic victory", and demonstrates by having Old Man suffer one when he manages to drink a gallon of milk in one hour, but gets a nasty case of diarrhea in the process.
Delita in Final Fantasy Tactics achieves peace and rulership of all of Ivalice... and loses absolutely everyone and everything he's ever cared about in the process. It really is Lonely at the Top.
All four Mega Man Zero games end like this for Zero and his group. Z1=Zero goes missing, Z2=the Dark Elf, the one who caused The End of the World as We Know It, was free and Mega Man X's body destroyed, Z3=Neo Arcadia is taken over by the Big Bad Dr. Weil and Z4=Neo Arcadia is destroyed, and Zero dead, for the last time.
If you don't do any of your partners' loyalty missions and rush through the game without making preparations, Mass Effect 2 ends with one. The Collectors are no longer a threat to humankind, but Shepard and Shepard's squad die achieving this, and the Reapers are still on the way. Wasting too much time before assaulting the base, on the other hand, can see Shepard too late to rescue the Normandy's crew - maybe thirty or so innocent people and allies.
Mass Effect 3 had the theme, "There can be no victory without sacrifice." One way or another, every major quest carries a penalty to match its triumph - some nastier than others, especially if Shepard doesn't exercise good judgement. And much like the previous game, going into the final assault without enough preparation can potentially cost you the war, even if you win the battle. The ending itself proves the Reapers cannot be eliminated as a threat without a heavy price, no matter which option Shepard chooses.
The outcome of the final battle, if you pick Refusal - your forces successfully punched through the Reaper lines and deployed the Crucible, which was the objective...but because you didn't use it, even with full readiness and about seven thousand points of effective military strength, a significant quantity of that strength has been wasted on a victory that achieved nothing.
Each Command & Conquer sequel reveals this is what happened for the last game. In Tiberian Sun, it's revealed that after Tiberian Dawn, Tiberium contamination spread to uncontrollable levels and while Nod is pacified, they have developed cyborg technology and several splinter cells are trying to take command. In Tiberium Wars, it's revealed that the cure discovered at the end of Tiberian Sun was not only ineffective, it caused Tiberium to mutate, becoming even more toxic than before and causing 80% of the world to either be thrown back into the dark ages or become dangerously inhospitable. By Tiberian Twilight, Tiberium not only took over the world, but threatens to kill off the entire human race within 6 years. Apparently GDI looses more ground with each game.
Infected has this at the end. You've managed to save New York by wiping out all the zombies! Congratulations! Too bad you only saved a few hundred people, at least the entire continental United States is still zombified, and there's no word from the rest of the world. But still...New York! Ayyyy!
The mission results screen for the penultimate mission of Ace Combat 04: Shattered Skies notes how victory over the Eruseans came at a very high cost of ISAF casualties, including many aces lost to Stonehenge.
At least two endings of Oracle Of Tao are like this. The best ending has the whole party teaming up to kill off the Big Bad, resulting in another boss, followed by a Playable Epilogue and a whole bunch of new endings. But if you don't meet all the prerequisites, you get secondary endings (the only one of which is actually good involves the use of a legendary sword). One of these involves the hero sacrificing all her energy and half-destroying the universe to kill it off (and STILL might not be enough, so you need some party members that will survive the event, namely your angel/demon characters) just to end the demon's rampage, and the second involves an exorcist ringing a bell that is deadly to everyone who hears it, taking herself out as well. Either of these losses completely wrecks party morale, and the group splits up thereafter.)
While the effect of the final battle wasn't immediate upon the protagonist of Persona 3, many players assumed that he was just sleeping when he closes his eyes in Aigis' lap on the final day of the game. It turns out he actually fell into his last coma and died soon afterward. The sequel, Persona 3: FES, shows us what effect the protagonist's death has upon the rest of the party. The reveal that the protagonist actually sacrificed his life to become the barrier between Nyx and humanity becomes the main point of contention between the entire party, especially for Yukari, who spends most of the game wanting to see him again, to the point where she would be willing to reset time even if it meant dooming the rest of humanity.
The bad ending of Persona 4 where you choose to kill Namatame. If you didn't kill him, he would have gotten away with it, right? But Nanako is dead, Dojima is left all alone, and your friends have to live with the fact that they killed a man who they weren't even sure was the true culprit. Heavy fog continues to envelope the world as you say goodbye to your friends...
Saya no Uta has this in all of its endings, to some degree. The worst example is the ending in which Kouji and Dr. Tanbo manage to kill Saya and Fuminori, but afterwards, Dr. Tanbo dies, and Kouji ends up more or less schizophrenic, and is horrifically traumatised, suffering constant nightmares. He keeps a single bullet in the cabinet in case it ever gets just that bad.
Kingdom Hearts: Birth by Sleep has all characters' endings like this. Terra loses his body to Master Xehanort but his armor and weapons reform by Terra's force of will and defeat his own body, stopping the current plan. However, Xehanort survives to become the Big Bad for the rest of the series, while what's left of Terra is just an empty suit of armor kneeling in the remains of the Keyblade Graveyard and stewing in anger at Xehanort for 11 years. Ventus defeats Vanitas inside his own mind destroying the X-Blade and stopping the other part of the plan. However the damage to his heart is so severe that he's rendered comatose while his heart seeks safety within Sora's. Aqua finishes off Xehanort's plans for good, except both her friends are gone, she inadvertently sets off the events that would put the first game into motion, and she's stuck wandering the Realm of Darkness alone for years. However, unlike most Pyrrhic Victories, there is the hope of Sora saving them all.
The Halo trilogy: At the end of the Human-Covenant War the humans successfully prevent Earth from being completely destroyed and permanently end the threat of the Covenant. However most human colonies are lost as well as basically the entire fleet and armed forces, and given that 23 billion humans died, there's barely anything left of their former interstellar empire.
The Covenant suffer one as well in Halo: Reach. Though the invasion of Reach was a complete success that basically broke the backbone of the human forces, they still loss 2/3 of their fleet trying to occupy and destroy Reach. Not only that, but they also were not able to prevent the Pillar of Autumn from escaping the system with the coordinates of an ancient Forerunner installation. The arrival of that ship on the first Halo in the first game directly lead to the end of the Covenant and prevented the total extinction of all humans.
Really, this is a habit with Bungie. The Marathon trilogy had only a handful of the Tau Ceti colony escape alive, plus the Pfhor angered enough by their defeat to pull a Superweapon Surprise as a final “screw you” (almost causing the destruction of the universe too through accidental stupidity;) Myth has pretty much your entire army slaughtered to a man over the course of the game, culminating in a Taking You with Me when you destroy the Big Bad; and Oni ends with the revelation that the entire planet is ecologically on its last legs.
Despite their noble decision to form a truce with humanity and aiding in destroying the loyalist forces, the Sangheili are no better off afterwards- without the means to create the vessels that they used (as they were creations of the Prophets backward-engineering existing Forerunner technology), their campaign against the Brutes is long and bloody. Worse still, they lack any spiritual guidance that they once had prior to their race being integrated to the Covenant, to the point where one Sangheili leader in the comic "The Return" revisits a planet he had glassed, simply to find anything that might rekindle their faith. Fortunately, after saving a human, he finds out about the existance of a Monitor, a lead he intends to follow to achieve the ends that he seeks.
The novel Halo Glasslands also reveals that Sangheili society is on the verge of imploding without the Prophets to maintain any sort of unity amongst the various Sangheili factions.
ONI's plan in destabilizing Elite was also successful but it will soon comeback to bite them in the ass, as they only created more enemies for the UNSC, as the Storm Covenant sides with the Diadact, and rally more Covenant to their side.
The Protoss ending in StarCraft I. The Overmind was destroyed but Aiur is now infested by Zerg. Crazy, disorganised and rampant Zerg.
The Brood War ending: the fighting stops and the Koprulu Sector settles down into relative peace for a few years, but not because anything's actually solved, more because everyone has simply exhausted their military forces and needs a breather to build them back up. Even the Zerg, who retreat to Char rather than push their advantage.
The ending of X-COM: Terror from the Deep not only results in the deaths of the best troops sent to fight the aliens, but also in the deaths of millions from poisons and global warming as the result of the destruction of the alien mothership.
The ending of X-COM: Enemy Unknown isn't much better - the global financial crisis following the war results in the collapse of most of the world governments. Also, the eventual depletion of Earth's only supply of Elerium-115 results in all Imported Alien Phlebotinum becoming useless.
If one takes Interceptor into account, while Earth is still a toxic mess, humanity uses alien technology gained in previous games as a stepping stone to a robust interstellar empire, one which successfully wrests control of the stars from hostile aliens.
The Bureau: XCOM Declassified ends with X-COM fighting off the Outsiders, but thousands of people are dead or have been transported to the Zudjari homeworld. Not to mention that, if we take Firaxis's Word of God that this is a prequel to their XCOM: Enemy Unknown, the fall of the Outsider Empire only leaves a galactic power vacuum that is quickly filled by the Ethereals. Subsequently, defeating the Ethereals results in the death of your most powerful psychic soldier, and the cryptic comments by the Ethereal leader imply an even greater threat out in the galaxy; and yes, you've just created another power vacuum.
Final Fantasy I: The heroes confront Chaos, destroying him and shattering the time loop. But because that loop is shattered, no one—not even the heroes—remembers there was ever a battle to begin with. The price of victory? Never knowing your greatest achievements ever were.
The Battle of Parsir in Mitsumete Knight. Sure, Dolphan won the fight in the end... But at the cost of one third of its army, due to enemy General Meehilbis'.
The canon ending to Blaze Union. The incompetent government has been overthrown, Gulcasa is able to completely ignore the corrupt court by becoming the world's most empathetic and competent dictator, and the people's lives can finally return to normal. Over the course of achieving this, the employer Gulcasa trusted and his Living Emotional Crutch died, his mother bullied him into killing her for the sake of reclaiming his true power, and his childhood friend and mentor tried to kill him out of fear that he might become a monster someday, leaving him a complete emotional wreck.
Three years later, just when his people's lives and his own mental state have stabilized, his attempt to rescue the rest of the world goes as wrong as it possibly can, and he is forced to watch everyone he ever loved sacrifice themselves for him as his country is ravaged by invaders, ending in his own death. Thank God for that gaiden where you can fix this.
In Dragon Age: Origins, a Human Noble PC's sacrifice makes it one for the Couslands. It becomes one for the PC if Alistair sacrifices himself out of love.
Crysis ending is kind of like this, to the point that the song that plays through the final battle is called Pyrrhic Victory. Nomad and Co. manage to destroy the giant alien ship and exosuit, but the entire fleet was destroyed and only Nomad, Psycho, Helena and Prophet survive the entire island ordeal. To make things worse, you only destroyed a single exosuit, and during the entire battle you see maybe hundreds of thousands leave the sphere on the island...
You can be told that you have suffered one in Total War: Shogun 2, though if you have truly broken the enemy army and don't have anyone else to worry about your forces will regrow naturally over time without you having to pay, making this a bit of a misnomer. That doesn't mean you can throw your forces away however, other clans may take advantage of your momentary weakness.
Same in Napoleon: Total War, where this troop replenishment model was first implemented. Unlike the previous games, where a seriously depleted elite unit would lose experience by diluting veterans with rookies (training only does so much), troops starting with Empire: Total War no longer suffer this effect.
The ending of Arc The Lad 2. Let's have Elc explain it, shall we?
Elc: It makes me wonder what we were fighting for. Arc died, and for what? So we could inherit this desolate and hopeless future? We didn't stop the world from ending, we survived it. And, now we are left with nothing.
The backstory and supplemental material of Portal explains that the Aperture Science researchers who built GLaDOS found out a little too late that her idea of "supervising the functioning of the Enrichment Center" involved, as a first step, murdering all of them with a deadly neurotoxin. Just prior to dying, the scientists managed to install a Morality Core to restrain her homicidal impulses, but it was far too late for any of them.
You can use this against Legate Lanius, commander of Caesar's Legion in the final confrontation of Fallout: New Vegas. With a high-enough speech skill, you can convince him that even after winning the battle for Hoover Dam, he would not be able to take on the rest of the NCR due to either a lack of forces or an inability to properly sustain his army. Being a Genius Bruiser with Hidden Depths, this is enough to convince him to retreat.
In Phantasy Star II, Mother Brain is destroyed, but that's no consolation. Palm, along with most of humanity, was already destroyed by Mother Brain, Motavia's terraforming and technological civilization will collapse without Mother Brain to control them, and most of humanity is too weak-willed by now to survive the desert planet that Motavia will turn into.
Phantasy Star IV shows that humanity on Motavia has mostly recovered, though it's still far less advanced than it was back in Phantasy Star II.
While the first Knights of the Old Republic painted the cannon Light Side ending as a fairly straightforward victory of the Republic against the Sith, (only made slightly bittersweet for the PC with Malak's regret before his death, and especially Bastila's possible death). As a part of its massive Deconstructor Fleet, the sequel went into more detail of the effect of the loss of so many resources, leaders, and most of the Jedi on the tired Republic, painting the Jedi Civil War as one of these.
In the second battle of Bothawui in Star Wars: The Old Republic backstory, the Sith forces have killed all of the Republic forces but suffered massive losses and couldn't keep a foothold on the planet so they decided to just leave.
The consequences of such a Pyrrhic victory hit hard in the sequel. The cost of victory in the first game is so high that the leader of the American forces, General Shepherd, becomes completely disillusioned and allies himself with a Russian extremist in order to incite war against his own country just to wake them up to what they've let themselves become. The belief that his men were lost in vain completely destroyed him. Modern Warfare 2 itself also qualifies as Shepherd is killed but far too long after the fact, not only having betrayed his own men and country, but getting what remains of his anti-terrorist task force marked as defectors and the war with Russia he started is unhindered.
In S.T.A.L.K.E.R.Shadow of Chernobyl, the best ending has Strelok stopping the C-Consciousness' ulterior motive of tampering with the noosphere by shooting their stasis pods and then escaping their secret lab by means of a portal off-screen. However, this caused the Zone to become even more unstable as emissions have run rampant on a daily basis, resulting in an increase of zombified stalkers, mutant activity, Monolith soldiers, and other nastiness. Call of Pripyat takes place after this ending.
The final boss of Killer7, Greg Nightmare plays like this. You beat him and get an insanely powerful weapon... at the cost of the six/seven recessive personalities, which have been Killed Off for Real.
The Final Summoning means that Sin (if defeated) doesn't come back for a while, and people can live peacefully. Except the Summoner dies, and one of their Guardians is transformed into the Final Aeon (and later the new Sin) to restart the cycle.
The party's collective defiance of Yunalesca's attempted But Thou Must means that all of the Aeons that have aided Yuna and the party on their journey must be sacrificed, and if that wasn't enough, Tidus can no longer exist in Spira if Sin is defeated; "winning by losing", to paraphrase Yuna in the sequel.
Final Fantasy XIII has the ending in general: The party defeat Orphan, because if they didn't (by Barthandelus' logic) another unfortunate Cocoon citizen would end up in their place eventually. While the world seems to be ending, Fang and Vanille become the crystal pillar and save the day. But they're both crystallized forever (unless they want Cocoon to come toppling down). And a lot of people died anyway.
The sequel also has fixing the timeline: doing so means that Serah will most likely die, but they do it anyway; the paradoxes all appear to have been fixed, time gates have closed forever, and Hope's new Cocoon is safely floating in the sky, with Fang and Vanille salvaged from the crumbling pillar. Then Serah dies. And then the victory itself is completelyundone.
Gears of War ends like this. The Locust Horde and the Lambent have all been killed, 90 percent of Sera has been rendered uninhabitable by the war, from the Hammer of Dawn Counterattack that destroyed huge portions of Sera to the Lightmass Bomb and the rise of the Lambent. 99 percent of humanity has been killed.
The players win in Guild Wars. The cost? You lose your homeland and your Prince. Your allies in the jungle die en masse. The Dwarven Prince also dies. During many of the missions you see countless peasants and allied mook soldiers die. You unleash an army of abominations on the world, but cut off the flow of new abominations. This ensures there are only enough rampaging abominations to destroy an entire race of powerful wizards. They keep rampaging after that job is done. Later expansions and the sequel were kinder and gentler (by comparison).
Guild Wars 2 reveals that while you stopped Abaddon from returning, Palawa Joko used the freedom you granted him to conquer Elona and destroy everything you had fought to protect there.
At the end of the Living Story you finally killed Scarlet Briar, but not before she devastated Lion's Arch and awakened the sixth Elder Dragon.
In fact, players have pointed out that Virion's strategy is just like the Spiteful A.I. that Fire Emblem has... they try to win without bothering to think about units' survival and happily send units to their deaths just to achieve one of these. Heck, in some games where you can make potentially infinite reinforcements, a lot of players would play just like this.
All of the canon endings in Fatal Frame tend to be Pyrrhic in nature. Usually, it ends with the protagonist solving whatever curse it was driving the ghosts to violence and finally allowing them to rest in peace... but at the cost of one or more of their loved ones. Only in Fatal Frame III is it possible (but difficult) to save everyone, but even then the nature of the story means the survivors are wracked with grief and probably in serious need of some therapy.
The storyline of Mirror's Edge ends with Faith saving her sister, which was the initial goal of her quest. But in the process, her mentor was shot and died before her eyes, and both her best friend and her former boyfriend betrayed her. Happy ending!
Any "victory" for humanity in The Tale of ALLTYNEX tends to be of this nature. In the first game, 85% of the human race is killed and the remainder have to fight a long, bloody 40-year war against the AI that did it to reclaim Earth. In the second game, humanity only survives by the skin of its teeth against the alien invaders, and gets knocked back into the Dark Ages in terms of technology. The invaders themselves retreat from Earth after all their military forces have been annihilated and their homeworld is on the brink of resource collapse due to the conflict. And finally, in the final game, Earth's civilizations have once again been nearly wiped out by an insane scientist who co-opts the weapons used to drive off the invaders to attempt to annihilate humanity for its transgressions.
The whole point of Nidhogg is to reach the other end of an arena and getting eaten by the Nidhogg.
A meta-example for La-Mulana. You slogged your way to the end of Hell Temple? Congratulations. Now you get to see Lemeza wearing a skimpy bikini. And if you're playing the remake, you get to see it through the rest of the game.
In the prologue of Drowtales, the Sharen won the war against the Nidraa'chal, but the cost was horrible for their clan and their city. In fact, it is an inversion: the Nidraa'chal were not destroyed, and they are the actual winners of this war, with only a few less, and had in fact infiltrated the clan from the inside and were founded by several of the clan's own royal daughters.
The end of the Dr. McNinja saga "Doc Gets Rad" has the doc trap Sparlelord in a infinite time-loop, preventing him from conquering the world. Of course, by doing this, he eliminated the one threat that could have permanently defeated King Radical, which Radical is more than happy to rub in Doc's face.
In Homestuck, the troll session ends with the trolls defeating the Black King and creating our universe - which allows the B1 Jack Noir to gain First Guardian powers, destroy all the planets in the trolls' Medium, including Prospit, Derse, and the Battlefield, and trap the trolls in the Veil for several weeks long enough for internal conflicts to kill off half of them.
In thisThe Whiteboard strip, Roger describes the aftermath of an indoor snowball fight (It Makes Sense in Context) as being a Pyrrhic victory after the use of a snowblower results in Doc's office getting three feet of snow dumped into it.
In Manly Guys Doing Manly Things, Leondias and Kratos get into a battle of gay chicken. After a long time, Leondias concedes defeat because he misses his family. Kratos taunts him for giving up just so he can go home to his family... but is immediately reminded that he has no family to go home to now.
The second Minotaur battle in Our Little Adventure. The Minotaur was killed sure enough, but it also killed Pauline, the group's Barbarian and beloved friend. What's worse is that she doesn't come back when Julie attempts to revive her at a temple, due to not wanting to.
In Tech Infantry, pretty much every battle in the story is one of these, if not an outright defeat. The first Jurvain invasion of Rios is destroyed, at the cost of a jump gate, then a rebel attack is driven off with such heavy cost in Council Loyalist ships that when a second Jurvain invasion comes in, there's effectively nothing to stop them. The rebel fleet attacks the Federation capital in Avalon, and is again driven off at the cost of such heavy Federation casualties that future offensive operations against anyone are pretty much impossible. And the Vin Shriak is defeated, at the cost of so weakening the Federation that they are powerless to resist a subsequent invasion by the Eastern Bloc and their alien allies.
The titular character of Doctor Horrible's Sing-Along Blog gets, in his own words, everything he ever wanted: respect as a villain, entrance into the elite Evil League of Evil, and the defeat of his nemesis. However, it costs him the life of the only woman he's ever loved before he's even been able to tell her how he feels.
Not to mention her last words. Can you imagine any satisfaction in his "victory" at all after something like that?
In the prequel comic that detailed Billy's past, it's shown that his inspiration was witnessing a Mad Scientist villain named Mister Maniacal successfully killing the superhero Justice Joe. Later on in the comic however, it's mentioned that Maniacal was soon killed by a lynch mob afterwards.
This◊ Erfworld story arc involves something on a smaller scale. Gobwin Knob has made a series of losing attacks on the Jetstone forces, which were reported to their commander as victories by the pseudo-magical "rules" that make Erfworld function like a tabletop game. It takes a couple minutes for someone to point out that, by attacking, inflicting losses, and retreating, the Gobwin Knob forces were technically losing the engagement but still inflicting critical damage on the Jetstone siege forces.
Red vs. Blue has the defeat of the Meta and dealing with Project Freelancer come at the price of Alpha-Church and several other AIs being destroy in a EMP, Tex imprisoned in the capture unit that Epsilon-Church then joins her in (which is thrown into evidence and deemed useless) and Wash almost killed, then forced to masquerade as Church to avoid prison time. Oh, and Red Team lost Lopez. He comes back (as a head still/again) in season 11, though.
The Whateley Universe has the Halloween battle. What was originally intended as a cover so that the Goobers could kill Sara Waite turned into a full-on attack on Team Kimba, with many others getting caught in the cross-fire, and it ended badly for everyone- while the Whateley crew won, they ended up with thousands of dollars of property damage, more than a few injured, a staff member dying and that triggering a rager attack by another staff member that turned him almost committing suicide because of the death of his girlfriend. It turned out worse for Englund, the instigator- almost everyone on the staff and more than a few students hated him even though they couldn't prove that he did it, the attack on Sara wasn't successful, and the staff member who went rager now wants to kill him with extreme prejudice. The Syndicate (the main evil attackers) lost hundreds of their soldiers, and the main general ended up nearly losing his boyfriend. In other words, nobody won and everybody lost.
In Worm, Leviathan is ultimately forced to retreat by Scion, but a lot of people are dead, most of the city is destroyed, and it is sheer anarchy in the streets.
In Mario Brothers, King Koopa and his army are defeated for once and for all... at the cost of the lives of Princess Toadstool, the Toads, and even the Mario Brothers themselves. The Mushroom Kingdom itself may even be doomed to destruction, since the last we see is the land being overtaken by the lava erupting from Koopa's castle.
In the Transformers episode "The Golden Lagoon", nature-loving Autobot Beachcomber discovers a glen full of organic life and a pool of "Electrum" which in this case is the opposite of Kryptonite. Cue both factions going through a never-ending battle to take command of the pool, destroying every single piece of life in the glen. Beachcomber's final words as he surveys the nuclear war scene? "We won..."
This is especially paradoxical, since the Autobots have explained time and again that their mission was to "protect life"...apparently, completely destroying a glen full of life in order to get to a major plot point doesn't count. But perhaps the message of the episode was on the tragedy of war: letting the Decepticons have control of a resource that would have made them invincible would have been such a disaster for all non-Decepticon life that it was better to destroy the glen than to let the Decepticons have it. A few must die that others may live; that's called war.
In Avatar: The Last Airbender , Katara comes across a elderly waterbender named Hama who teaches her on how to improve her Waterbending skills, albeit through questionable methods. Her last lesson is Waterbending's ultimate technique, Bloodbending, where under a full moon the Waterbender can take complete control of his opponent. Katara, of course, is horrified at such a practice and vows not to use it. But when Hama takes control of Aang and Sokka and nearly kills them, Katara has no choice but to use the technique to stop her. Hama laughs at this while she's being carted off by the officials, as she succeeded in making Katara use the technique much to Katara's dismay.
Even more Pyrrhic if you count Legend Of Korra. Bloodbending survives and gets better despite Katara not passing on the art. It's used by two Big Bads and one Big Bad Wannabe to devastating effect.
In Chaotic, "Allmagedon", a creature uses an attack to defeat an army of underworlders, at the expence of all he was trying to protect.
In Duck Dodgers in the 24½th Century, Duck Dodgers and Marvin the Martian are fighting over Planet X. They both finally deploy doomsday weapons, blowing the planet up and leaving a chunk so small that it literally isn't big enough for the both of them. At this point, Dodgers shoves Marvin off the planet and starts gloating about his victory, while the camera pans down to reveal the Space Cadet is hanging on to a few roots, saying "Big Deal".
Aelita willing makes a Pyrrhic Victory at the end of "Sabotage", a Season 3 episode of Code Lyoko. In this episode, X.A.N.A damages the Supercomputer and puts a lot of guards on the tower. Jeremie needs the active tower off-line so he can reboot the Supercomputer but Aelita can't get past the guards to use the "Code Lyoko" code — so she willingly uses "Code X.A.N.A." code to delete the Ice Sector. allowing Jeremie to reboot the system and stopping active tower.
Cartman has one of his victories become phyrric in the South Park episode "201" when Scott Tenorman reveals that his father and Cartman's were one and the same, meaning Cartman killed his own father along with Scott Tenorman's mother when he fed them to him as chili for revenge in "Scott Tenorman Must Die" nine seasons prior. Cartman however is more upset that this technically makes him ginger rather than the fact that he killed his own father.
Numbuh 363 from Codename: Kids Next Door caused one in "Operation I.N.T.E.R.V.I.E.W.S.". He brags throughout the episode and hates being touched. He also refuses to help Sector V when Count Spankulot spanks them. Finally, when Numbuh 1 saves his life from Father and he is waken up with Father's Pipe, all he can say is "I WIN! I GOT THE PIPE!". His own sector is appalled by this that they betray him and gag him and give Sector V all of their stuff. What a true winner.
As mentioned to Shayera Hol in the Justice League Unlimited episode "Hunter's Moon", because she had stopped her people from trying to destroy Earth just so they could create a shortcut to the Gordonian home world and win the war, her former lover and commander Hro Talak ended up sacrificing himself against the Gordonians which resulted in a great loss for the Thanagarians.
Bugs Bunny finally beats Cecil Turtle only to have a cop write him a traffic ticket because of how fast he was going in order to win. There have been no more Bugs-Cecil cartoons apparently because Bugs was satisfied with actually winning for once, pyrrhic victory or not.
Subverted in ThunderCats (2011), with Grune and Panthro. Grune coins the line "No price is too great for the defeat of my foe" when he rips out his own fang to slay a giant spider. Panthro repeats it when he lets his arms get cut off to ensure Grune's death.
Panthro: Looking down at his severed arms "Worth it".
In the second episodes of Static Shock, Virgil feels this is the case even though he beat Alfa and Hotstreak because the evidence against Alfa was destroyed.
A few episodes of Danny Phantom end like this, most notably "Public Enemies" where even though Danny manages to beat back Walker's forces, Walker manages to succeed in his plan to make Danny a Hero with Bad Publicity. True, Danny managed to turn it around eventually, although it did stick for awhile.