Sarah Kerrigan from StarCraft ran away from the memory wipes and torture of Ghost Training mandated by the corrupt Terran Confederacy to join a rebel grouponly to be betrayed by its leader and left for dead in the middle of zerg attack. And then being experimented on, until becoming a Tragic Monster.
The titular character of American McGee's Alice and its sequel Alice: Madness Returns is quite the cold snarker - then again, considering that her sister was raped and murdered, she was the only survivor of a fire that killed the rest of her family right before her eyes, and she was incarcerated into a Victorian asylum where she underwent horrific treatments, you can cut the poor thing some slack.
Over the course of the game, Aribeth gets quite thoroughly shattered. By Hordes of the Underdark, what with her whole failed revolution and crisis of faith, she is definitely one.
Alex from the fan-made module The Bastard of Kosigan has her childhood boyfriend exiled from their homeland, getting involved with his insane older cousin, getting pregnant and having him and his soldiers beat her until she looses the child, being considered an embarrassment to her family, and being forced to work for the same man who got her pregnant and dropped her like a hot brick?
Almost every major female character (and some male characters) in the Dragon Age series. To recount:
Leliana: former Orlesian assassin, betrayed, tortured, and raped on the orders of her beloved mentor (and lover) before the game begins. The sweet, pious Chantry sister started out as an act. She manages to actually subvert this beautifully: as her own narration and, more importantly, Leliana's SongDLC reveals, she has suffered enough traumatic experiences (betrayal by a loved one followed by brutal torture) to break another woman many times over; however, just as she was about to crawl into a hole and die, she got religion and started having prophetic dreams, one of which directed her to the Warden. At the end of the day, Leliana is easily the most cheerful and caring person you will ever meet in the game, strengthened by her ordeal rather than broken by it.
The subversion is slightly tempered if the player "hardens" her. She's still a fairly positive and friendly person, she's just more willing to murder problems, and more tolerant of some of the Warden's potential amoral actions. She ends up playing it straight in Dragon Age: Inquisition, however. Reneging on the promise of having your choices matter, Leliana is written as if she was hardened in Origins regardless of whether or not she was. In addition, she largely blames herself for the death of Divine Justinia in an explosion she couldn't have forseen and was frankly just lucky not to be blow up in herself, since part of her job as the Divine's Left Hand was preventing things like that. As a result, she starts questioning her faith and is even a little too eager to Shoot the Dog in pursuit of goals. The player can effectively "un-harden" her through dialogue options and her personal quest by getting her to stop blaming herself for Divine Justinia's death.
Morrigan: raised alone in the wilds by Flemeth, with little to no human contact of any kind and no experience relating to others in any way. Sent off by her mother to bear a child to a Grey Warden she may not even like. Granted, she's less broken than twisted, and there is little evidence that she ever had a more cheerful personality that changed as a result of a traumatic experience, making her a possible subversion.
The Warden: depending on your Origin, many, many possible nasty things happen to the Warden, all leading to long-term exile from home, though you can choose to play the angst as much or little as you please, and the Warden will always be some flavor of The Stoic.
Velanna: bears all the hatred of her people for past wrongs done to them by humans. The Warden first meets her attacking caravans after she was manipulated into believing the humans wiped out her entire clan and took her sister captive. Turns out, it was darkspawn, yet her people hold her responsible for the diplomatic mess that followed, so she ends up exiled and with the Grey Wardens. That she's a bit cranky is not much of a surprise.
Merrill: banished from her clan for trying to help them restore their former glory, she starts taking on more and more traits of this trope as the game goes on and her efforts get more desperate. Depending on Hawke's actions, her continued attempts may be destroyed; later, she is forced to watch her estranged mother figure pay the price for her trafficking with demons.
Isabela: as revealed by her romance backstory, she was sold off by her own mother at an early age to a merchant captain, and ended up sleeping with the assassin who killed her 'husband' to thank him, starting a long train of piratical activities and lots of sex to disguise her severe troubles with emotional intimacy.
Bethany: ...where to begin? Though this is largely only if she ends up a Grey Warden. If she ends up in the Circle, she retains much more of her stability, though the reason she willingly went with the Templars is because of severe self-loathing issues born from how much her family has been burdened by hiding her magic.
Hawke: Forced to Watch Kirkwall and his/her family disintegrate around her. Most of it is his/her fault. Averted if you play Snarky!Hawke or Paragon!Hawke the whole way through, aside from a brief period of depression after his/her mother is murdered, though plenty have pointed out the possibility of Sad Clown and/or Stepford Smiler at work.
Fenris actually fits the trope description very well, despite being male. Most of his conversations with Hawke are just laying out how much of a mess his life is.
Visas Marr in was spared by Darth Nihilus when he killed every other living thing on her homeworld, and was raised by him as a Sith. For a light side character, turning her back involves restoring her hope that Nihilus can't kill every living thing in the galaxy.
Meetra Surik, aka The Exile, despite being the only one to return from the events of Malachor V alive or not fallen to the dark side. The destruction of the planet accompied with the countless numbers of Mandalorians, Republic soldiers, and Jedi being annihilated—all of it she could feel through the Force to the point it was so overwhelming she had to cut herself from the Force otherwise die or fall prey to the dark side; and consequently made her a wound in the Force. Since then she had become a broken figure as the pain of all the destruction of Malachor V stayed with her. Numerous times within the narrative she is called a "broken Jedi". Given the events they both suffered, it easy to understand why Visas and Meetra could so easily relate to one another.
Visas: To see everything around you extinguished... it... was as if I was blinded. It was as if the Force had... been bled from the world... Exile: ...as if everything suddenly went silent. Visas: I imagine there are worse deaths, worse pain, but if there are, I do not know them. I was the only living thing remaining on the planet of Katarr... and my life, my agony was a flicker in the darkness that was the planet.
The reason Rose is one is because she's actually the black monster, and has committed countless atrocities simply to keep the Big Bad from getting his way. It fails.
Miranda was abandoned by her father and abused by her mother, until the point that she ran away from home and became adopted by the queen of Mille Seseau. She serves as the First Sacred Sister, and slapping someone tends to be her default reaction.
Raven Rune Factory 3, who you eventually learn has had every single person that she's ever become close to disappear, and she's positive that it's because she's cursed. So, she's vowed never to have another friend. She definitely has the violent part of a Broken Bird, what with her semi-accidentally shoving your character off of a cliff at one point, and in her later requests, she's very prone to tears. She's also about as literal an example as any Broken Bird can get.
In Fire Emblem: Shadow Dragon and the Blade of Light, we have Princess Minerva (forced by her evil brother Michalis to fight for him to protect their sister Maria) and Princess Nyna (last descendant of the Archanea family, plagued by how much Love Hurts. The remake adds Katarina aka Eine, a badly-abused Tyke Bomb who can get better if you manage to recruit her. (And Eremiya, the person who made Katarina the person she is... but we only learn about it when we see her tragic backstory.)
Miranda (to Leif): "It all started when you fled from Leonster. My father was a kind man who loved peace. He had no reason to go against the Empire... But...but...! Just because he hid you, we were caught by the Empire and attacked! My father was forced to turn me over as a hostage and lost his right to his throne...he died a miserable death. I will never forgive you, Prince! If only you hadn't come to Alster...this never would have happened...
According to Pent and Louise, Louise's cousin, Queen Hellene of Bern, is one as well. She used to be a sweet ojou who wanted to be happy in her married life, but her Arranged Marriage to King Desmond turned out to be a really crappy one, and she ended up as a cynical and manipulative Hot ConsortRich Bitch.
Pent: "She and the King were ill-matched. She has suffered much. (...) Such a sad life"
Believe it or not, Serra is one of these too. Yes, that Serra, the Genki GirlRich Bitch who is actually a Stepford Smiler with a childhood full of abandonment, poverty, and pain.
When we meet Florina's Proper Lady sister, Fiora, she's dangerously close to broken bird-dom due to having lost all of her wingmates... Flori has to quickly talk her out of going into a suicidal Foe-Tossing Charge, even! In her supports, though, we see her slowly getting better thanks to people like Florina, Farina, Kent, Sain, and Eliwood.
White Magician Girl Ninian. Well, you can't expect less from a woman who is a half-Dragon, survived the Scouring as a little girl, had to run away with her little brother Nils, lived for centuries in another world, and once she and Nils tried to come back home, were hit with misfortune by the bushel.
Female Dragon Rider Vaida and Lady of War Karla. The first was treated as a traitor, demoted, humiliated and had to work for the Black Fang; the second is the sister of Karel the Sword Demon and has dedicated her life to defeat other fighters and look for him after he murdered their family.
Soren is distant, bitter, and cynical towards every single person not named Ike. It's revealed in their supports and bonus scene that Soren was badly abused and left for dead during his early childhood and Ike was the only one who offered him any semblance of kindness accounting for his behavior towards Ike as well as others.
Reyson is unwilling to let go of the events that killed his entire family or so he thinks, really only some of his relatives died there and holds a twenty-year-long grudge against all "humans" (used in-context as a fantastic racial slur). He even seriously considered using forbidden magic to destroy them, until his guardians talked some sense into him. Bonus points for being able to transform into a literal bird, of a race known for how calm their minds are.
Cordelia is a serious, stoic, kind Pegasus Knight with two huge inner pains: the deaths of her wingmates and her Unrequited Love for Prince Chrom.
"Marth", or better said, Chrom's daughter Lucina, is a more idealistic example. She and her friends from a Bad Future try changing it, and as the group helps her to do so, she starts to slowly heal from the terrible trauma she has been through.
Princess Camilla of Nohr was badly, badly damaged by her turbulent early years in her country's bloodstained Decadent Court. At best she'll be a Cool Big Sis to her subordinates, her siblings and specially the Avatar; at worst, she'll try to kill the Hoshidan troops in despair to try getting the Avatar back home.
Princess Azura has more than one trace of this, as a Princess who doubles as a Child of Two Worlds who was badly abused in Nohr and badly discriminated in Hoshido. As a result, she has a very low sense of self-worth, seeing herself as a Replacement Goldfish for the Avatar, and a plethora of trust issues.
Jakuri from Ar tonelico II: Melody of Metafalica is not only a perfect example of this trope and its sub-traits, being simultaneously Tsundere and more than a little goth, but is known for singing hymns in which she uses the imagery of a little bird as a metaphor for herself, a theme first seen in EXEC_HARMONIOUS/., the song she crafted when she was better known as the first game's antagonist, Mir.
Planescape: Torment's Annah is an orphan, a distrusted descendant of fiends, raised by a money-grubbing corpse-seller, trained as a thief, and has the rather interesting experience of seeing one of the corpses she sells walking around again later—and not as a zombie. Then, the only father she's ever known is killed while she's off helping said "corpse", against her will, except said parent ordered it, all before she's even really an adult. She hides her issues well, but occasionally, they'll slip out.
Big Boss: Ever since the day I killed The Boss... with my own two hands... I... was already dead.
Mass Effect: As with every other character trope in the book, you can play Commander Shepard as one of these. The prize for Broken Bird, though, has to go to Talitha, the slave girl you can rescue in the Colonist's optional sidequest "I Remember Me".
Jack: "Turns out, mess with someone's head enough and you can turn a scared kid into an all-powerful bitch." Besides undergoing the training to be a Biotic Tyke-Bomb, she's revealed the times she's been sexually abused. When the sexual assault is the least traumatic aspect of a character's backstory, you know they've had it hard.
Liara becomes one by "Lair of the Shadow Broker", especially if she was Shepard's love interest in the first game.
Miranda Lawson to a large extent, though she hides it well at first.
And some of the men, Kaidan. (Admittedly, it's been years since he killed that turian...) Garrus in the sequel as well, given the whole Archangel thing.
Shepard has definitely become this by Mass Effect 3. Everything that s/he's experienced through all three games and his/her attempt to suppress those emotions for the squad's sake really begin to take their toll on him/her. Beyond that, in the From Ashes DLC, it's clear that Colonist Shepard hasn't completely dealt with all of his/her demons from seeing his/her family murdered and Mindoir destroyed when s/he was a teenager.
Shepard: They rebuilt Mindoir. (Quietly) It wasn't the same.
If Kelly Chambers survives 2, you can encounter her in 3, but the trauma of nearly being melted down has left her extremely fragile. If you react to her confession that she was spying on you for the Illusive Man with anger, she will kill herself.
Mira Kagami of Tokimeki Memorial 1, who, after having been dumped by many boys in Junior High because they didn't find her pretty enough, went the Revenge of the Nerd route in High School, by constructing herself as a beautiful and haughty Alpha Bitch, and gaining satisfaction at crushing the feelings and hopes of all the boys who fawn over her.
Kaori Yae of Tokimeki Memorial 2, who, after having been betrayed and ostracized by her friends at her former High School after Taking the Heat for them, grew cynical and extremely distrustful of the others, isolating herself from them.
In Brütal Legend, Ophelia is broken by certain events (in addition to her dark heritage) so badly, her sublimated pain and sorrow become the second strongest boss in the game. She is fixed by the end of the campaign (though not quite, it seems).
Male version: Fei Fong Wong from Xenogears. The theme song "Stars of Tears" even lampshades this in the lyrics.
The waves of time take me deeper into you A haze as blue as summer skies And turn to find the key will not unlock the door This broken bird away it flies
Haru from Shin Megami Tensei: Devil Survivor is tough, edgy, and very, very fragile as a result of her childhood. If the player does not choose her event to save her, she commits suicide halfway through the game. She was already broken even before the Tokyo Lockdown began. A musician who came from a troubled family, her mentor went overseas and she thinks that it's her fault when she was actually kidnapped by a Religion of Evil, and to top it all off, she's being hunted by demons because her songs are the key to summoning them to the real world.
Lightning from the Final Fantasy XIII series is a tough-talkingsoldier who has been burdened by the death of her parents and the subsequent responsibility to be the head of her household and take care of her younger sister Serah. The painstaking journey she's forced to go through to defy the gods and save the world only serves to increase her sufferings.
In addition, Hope becomes one of these by the end of XIII-2. After working so hard to save not only his friends but the entire world, and then watch it go down in flames around him it's no wonder he went from optimistic to completely shutting down.
Arguably, Cloud of Final Fantasy VII is one of these in the spin-offs of his main game. While he was never really cheerful, the character of the main game could be goofy, playful, and encouraging to his friends. In the spin-offs he's infamously become an angsty, stoic Anti-Hero due to witnessing the massacre of his entire home townat the hands of his former hero, then suffering through four-five years of inhumane experimentation, followed by witnessing the death of the person who saved him. The trauma from this was so bad that at the beginning of his game Cloud adopted a false personality and fake memories just so he could function properly. Then during the game itself he underwent Mind Rape thanks to Sephiroth, witnessed the death of Aerith, and learned the truth about his horrible past in an excruciating manner. Honestly, no wonder he angsts!
Playable Caster (Tamamo-no-Mae) from Fate/EXTRA. She is extremely cheerfully, more Genre Savvy than most otakus and her insanely cute 'mikuuun!' verbal tics doesn't help. However, has one of the saddest backstories in the entire Nasuverse: she was divinity, but humans fascinated her so much that she threw everything away so she could go join them and help them in the mud, she lived to serve, to love them. What does her husband do? He sends an army to kill her when he finds out she isn't human. She spent three days fighting, killing and being bathed in blood in the field where she made her last stand. Every second of it was spent crying and shouting for her husband's forgiveness. Her biggest wish was to be the best wife in the world. That was thousands of years ago. It still is.
Chizuru Kagura, due to her twin sister Maki's murder and the heavy burdens that the Yasakani-Kagura-Kusanagi bonds bring to her. She gets better thanks to Mai, King and King's brother Jean, though.
Riven of League of Legends, who saw the ideals she dedicated her life to get shattered during the wartime atrocities between Noxus and Ionia. She fights using a broken sword, and as she herself puts it, "The sword mirrors its owner." Even her signature move is called "Broken Wings"!
Yelena Fedorova◊, a boss of Deus Ex: Human Revolution, saw her entire family die when she was only a little girl. The experience was traumatic enough to render her nearly mute, even when she dies. It also causes her to become an Ax-Crazy, dual SMG-wielding assassin with the ability to become invisible.
Shadowrun Returns: Dragonfall's Glory used to be a member of a cult. After the Adversary tricked her into murdering her mother, she installed antique cyberware to shred her Essence, leaving her almost incapable of feeling anything. Keeping Old Scratch from being able to affect her was the main goal, though.
Erana is a half-faery woman of remarkable magic power, who spent her life traveling the world creating places of safety and healing and fighting evil wherever she could find it, as Rakeesh calls her "a Paladin in all but name." And then the Hero learns that her wanderings were often because the Faery Folk rejected her because of her human heritage, and humans didn't accept her because of her fey parentage. This led to significant issues with her self-worth that feeds her self-sacrificing nature, and led directly to her death fighting Avoozl. If the Hero chooses to rescue her from Hades and does not successfully court her, she'll sacrifice herself to the Dragon in Quest for Glory V, as well.
Katrina is a human woman who also has very powerful magic, which many of her superiors and contemporaries at W.I.T. found threatening. By the time of Quest for Glory IV, Katrina was now the Dark Master and a vampire. She was turned against her will by the previous Dark Master, who lured her in with promises of great power but instead bit her and made her his slave. The game hints that Katrina had been used and hurt by men in the past, though the details are left obscure. She has long feared being powerless and vulnerable, which drives her plans in Shadows of Darkness. If the Hero tries to tell her he loves her, she accuses him of lying and claims the only person who genuinely loved her was Tanya, the daughter of the local innkeeper whom she took in and turned as her own daughter because she believed the girl's parents mistreated her and didn't truly love her.
Mitsunari Ishida from Sengoku Basara is noted by many characters to be a sad and angry revenge driven man who's lost his purpose in life after the death of Hideyoshi (his lord) at Ieyasu's hand in the third game. Granted, he's not any less angry in the fourth game in which Hideyoshi's still alive, though his emotional instability is a major plot point for other characters, even Ieyasu himself, who is willing to let Mitsunari believe that he killed Hideyoshi so that he has something to live for.
Dead or Alive: Ayane shows signs of it due to her rejection by her village. She's very committed to her lifestyle as a shinobi but comes across as cold and unfriendly compared to Kasumi or Hayate. She also drove herself to become a worthy master of her clan's fighting arts in order to gain recognition (another trait of the trope). The scene in Dimensions where she tries to kill herself after a fight with Hayate just goes to show how broken she really is.
BlazBlue: Litchi Faye-Ling, at first introduced as a local Cool Big Sis who is kind and pleasant to everyone, hid a severe Guilt Complex about being unable to save a friend. Her attempts to save him always lead into dead ends, then she found out she's dying of the same corruption and no one is willing to help her, just telling her to just deal with it, eventually she ends up Forced into Evil and helping the bad guys' genocidal plans, which still didn't help her any and she's marked by her former co-workers as a criminal that needs to be arrested. By BlazBlue: Chrono Phantasma, her sense of self-worth has been utterly destroyed and she sees herself as beyond salvation that the only thing she can do is to push on to save her friend, and anytime she acts like a cheery Cool Big Sis afterwards, it's obvious that it's a Stepford Smiler act.
Nobody... nobody can even save me anymore. I'm sorry...
It's also telling if you look at the evolution of her splash arts. In Calamity Trigger and Continuum Shift, she can afford to give a smile or a sense of confidence. In Chronophantasma, she's no longer smiling and looked rather empty and sad.
Most of the cast qualify (sans the Big Bad Duumvirate), but listing them all would take all day.
Lynn, Edward and Abigail from Witches' Legacy are all this, evil witches having destroyed their families leaving them all orphans. Lynn is lucky to have Carrie who is able to protect her from Elisabeth, though she isn't left unscathed and Edward is taken in by the witch hunters who teach him to hate wicthes until he meets Lynn. Poor Abigail has no one to protect her and is subjected to the full force off Elisabeth's manipulations - so much so that she even spends some time as a bird.
Fallout 4 has the Vault-Tec Salesman from the beginning of the game. A happy-go-lucky Pre-War man who'd be working for the company for twenty years, only to be turned away at the Vault door when the nuclear bomb goes off. He survives the blast, but the heavy radiation mutates him into a ghoul, and he watches society crumble for 200 years. He's not only lost everything and everyone he knows, the people in the Wasteland are pretty dismissive of him when he tries to help. To top it all off, the Sole Survivor shows up looking young and vigorous. By this point, he's bitter and lonely about everything that's been lost. A sufficiently charismatic survivor can convince him to let go and forge a better tomorrow in his settlement, returning him to a sunnier personality.
After everything that's happened to him in The Legend of Heroes: Trails of Cold Steel II, Rean Schwarzer is a male example of this trope happening to him as a series of things happen to him. In order: he failed to bring his friend back to the academy with him with said friend losing his life to protect and give him an opening to rescue the crown prince, he finally sees his biological father again after so long only to reveal that he was the Evil Chancellor all along, said chancellor forces him to be a national hero and forces him to go to war with Crossbell, a country he has no reason to even go to war with, and by the time he gets back to Erebonia, he snaps at the lady officer who has helped him because she's aligned with said Evil Chancellor and might have known about his heritage (she had a hunch but had no conclusive evidence). After all that, he finally unloads all of his grief to Towa but then Class VII leaves him to pursue their dreams, something he gives them his blessings for plus Class VII would have been dissolved anyway thanks to said Evil Chancellor.
The protagonist of Tales of Berseria, Velvet Crowe, starts out as a normal 16-year old girl. Then her brother-in-law Artorius ritually sacrifices her 11-year old brother, cuts off her left arm, beats the crap out of her, and throws her in a pit for three years to subsist on nothing but daemons. By the time she gets out, she's become an embittered wreck obsessed with getting revenge on him.
Sylvanas Windrunner of the Warcraft franchise started out as a noble and heroic ranger-general of her high elven homeland and fought valiantly in defense of its people against Arthras and the Scourge, only to not only be defeated, but denied a clean death, when she was raised as a banshee and forced against her will to watch and participate in the destruction of her homeland and its peoples. A chance weakening in the mind-control allowed her the freedom she needed to return to her body as a Revenant Zombie and form an alliance of fellow undead to avenge herself and her people. Having fulfilled her vengeance but abhorring her undeath as a curse, she attempts suicide in order to reunite with her fallen kin, only to be greeted with a vision from the Val'kyr that informs her of the void that awaits her, and the sight of Arthras being reduced to a sobbing wreck, before being revived by the sacrifice of the Val'kyr. After all of this, she's been driven by a fear of death, a general sense of distrust stemming from the Fantastic Racism from other people towards her and her current people, the Forsaken, and an increasing sense of nihilism.
Beyond: Two Souls: Jodie Holmes is a girl with a psychic connection to a spectral entity known only as Aiden. Abandoned by her parents and raised by the army to become an assassin, then she's betrayed, on the run, homeless, and almost Driven to Suicide at various points. Thanks to Aiden, she's still able to take on entire SWAT teams who go after her.
Yakuza: Cheerfully subverted by Haruka. Before the first game is over, the poor girl, then at the ripe old age of eight, has already seen more traumas (all of which are spoilers) than most people do in a lifetime. Hell, Haruka is introduced, eight years old, sitting and clutching a gun in a room full of corpses. You'd expect at least some form of damage to shine through. But no. Haruka is a kind, selfless, cheerful and optimistic girl, and her frequent confrontations with the darkest side of human nature do nothing to break her spirit.