This is based on opinion. Please don't list it on a work's trope example list.
Tearjerker / Dynasty Warriors
The final ending to Dynasty Warriors 7 is symbolic in a number of ways. From the game's perspective, it's bittersweet (and of course follows the story); Shu is conquered by Wei, Wei headed by Sima Zhao wins he major conflict of the war, Sima Zhao dies the following year, Sima Yan overthrows Wei and established Jin, and (While the game doesn't delve into it) Wu is eventually felled years later. The establishment and scenes of this, which showcases the heroes of Shu, Wei and Wu (and Lu Bu) duking it out and glorifying their deeds on the battlefield, gives you a sense that their era is over, and the final shot of Cao Cao, Sun Quan and Liu Bei, engulfed in a fire and showing an empty throne with likenesses of Sima Yi, Sima Shi and Sima Zhao over it is symbolic that, in the end, the efforts of the Three Kingdoms all came to naught and were conquered by Jin. On the bright side, though, it means China is finally united, and a new era of peace can finally begin.
The fact that the throne is empty is a sad symbol too: by the time the land is finally united, all the player characters, with the possible exceptions of Liu Shan and Wang Yuanji, have passed away. Actually Historically, only Jia Chong and Wen Yang lived to 280 C.E. Most of those who fought to bring peace and unite the land never lived to see it.
The presence of this alone is also a really strong feeling; after 6 previous games, the true ending to the Three Kingdoms is shown.
Sadly, if you read the history around which Dynasty Warriors and Romance of the Three Kingdoms are based on, you find that just 10 years after the land is united under Jin, Sima Yan dies, and a 16-year civil war begins between the various Princes of Jin...
With the above in mind, everyone in Dynasty Warriors - Wei, Wu, Shu, Jin - basically died for nothing. It's especially stinging because Sima Yi's legacy has been that of more than a dozen imbeciles fighting tooth and nail over the throne, which put China in an even more chaotic position, arguably, than the Three Kingdoms. China wound up in a dark age from 300-600 AD, when the Sui Dynasty managed to FINALLY unite a fraction of China and attain some semblance of order. True reunification will have to wait until 618 C.E, when the Tang Dynasty was established.
The struggles of the Three Kingdom heroes, while ultimately futile from their point of view, ensured their legacy continues on even after some 1800 years later: The main characters and stories of the Three Kingdoms period are far and away more well-known and remembered than entire later dynasties in mainstream Chinese culture.
This also makes Sima Yi's statement in his ending in 9 about telling his sons to raise worthy heirs very tragic. Shi dies without a son and Zhao chooses his oldest son, Yan, as his heir. Later, Yan establishes the Jin Dynasty after overthrowing the last Cao Wei emperor and reunites the entire land after conquering Wu. But his decisions to give his male family members higher position and to keep his developmentally disabled son as his heir led to an ugly Succession Crisis that fractured China once again, making all the efforts of his and his father and all those who had been fighting for reunification pointless.
Go play Da Qiao's stage in Dynasty Warriors 7 XL and witness how happy she is with Sun Ce and how he claims they will be together forever. Then play Xiao Qiao's stage and see how sad and brokenhearted she is since it's been years since Ce died. You'll feel terrible if you know your history and how he died and she was the last person to see him and knowing how she must feel that her husband is gone and she is left to live on.
Guan Suo's, Yue Ying's, Xing Cai's, and Ma Dai's death speeches in the final level of Jin the Capture of Chengdu, each one lamenting they didn't have the strength to fulfill the dreams of the ones before them that despite doing everything they could it was all for naught, especially if Shu's your favorite of The Three Kingdoms.
8's Guan Yu's death report. His surviving children are the ones that delivered the news, and it's pretty gut-wrenching to see Guan Suo collapsing to his knees due to being denied the chance to defend his father for his own safety, and Guan Yinping openly sobbing and weeping. Not to mention even if Guan Xing was delivering the news without emoting, his face is not seen (so we don't really see if he's got tears on his face)... but his speech is a little disjointed and shaking, signifying that he's also pretty crushed on his father's death. And even if Liu Bei didn't go for the 'roaring' route in his vengeance declaration, it's still a powerful scene to see him apologize to Sun Shangxiang for what he would do in face of all these.
The battle beforehand is also a complete tear jerker, things go from bad to worse as the battle rages on. Guan Ping's death to buy the rest of his family some time, complications continue to mount up as the Wu ambushes them, their own allies can't even come to their aid and Guan Yu's own men betraying him. It is especially heart wenching if you completed the hypothetical objectives as Xu Shu laments that he was powerless to prevent this tragedy.
If you were on a normal run or the first time, this might look a little normal, as they come really unprepared and lacking backup plans. But after you unlock the hypothetical route, this takes into a bigger Tear Jerker because Xu Shu was already there to offer his help that could save the day, yet you made Guan Yu ignore all those and lead to all those tragedies. In fact, this can apply to every second run of the historical route, which can make you lament "Why didn't I choose all those alternatives so this doesn't have to happen!?I was so stupid..."
7 has a more emotional response from Liu Bei regarding the deaths of his sworn brothers. When Zhao Yun tries to remind him that Wei is the real enemy, Liu Bei angrily brushed it off and wanted to go after Wu to avenge Guan Yu. Then, a messenger came and informed him that Zhang Fei was betrayed and beheaded by his own men who defected to Wu. Liu Beiís response of his other sworn brotherís death is so heartwrenching that not only he stood and staggered a bit, he smashed his chair with his sword while yelling The Big No, dropped to his knees and screamed in anguish. Itís even sadder than his wife dropped to her knees when she listened to the messengerís report on Zhang Fei.
The deaths of Guan Yu and Zhang Fei marked the beginning of Shuís collapse when Liu Bei decided to go on a revenge spree on Wu, neglecting all the virtues that he had been fighting for. But he failed, got sick and died. Shuís future didnít look bright when his son took over.
9 ups the ante by turning Zhang Fei's death into a cutscene. The fact that it's not a mere 'soldiers kill Zhang Fei in his sleep' doesn't make it any better. Zhang Fei held a banquet in preparation of Yiling (but after he abused his soldiers out of anger) until he noted a suspicious figure. He pursued the figure and it turned out to be his own men trying to assassinate him. He managed to subdue one, but then he's fatally backstabbed, and as his sight and body grew weak, all he could mutter was an apology to Liu Bei. It didn't sound that bad, until you realize that his whole family (Xiahou Ji, Zhang Bao and Xingcai) were all there in the party. One can just imagine just how a supposedly normal and relaxing (minus the fact that Zhang Fei was pissed off at Guan Yu's death) suddenly turn really sour with that one sudden death...
Zhang Bao's death in Chencang if you didn't fulfill the requirement to stop the ambush. Bao died in both Guan Xing and Xingcai's arms after succumbing to his wounds via ambush. Previously, he made a promise to swore an oath of brotherhood to Xing after the whole thing. His last words are immediately acknowledging Xing as his sworn brother even before the oath took place. What follows is the only time Xing openly breaks down with aBig "NO!".
In Dynasty Warriors 7, you spend a good bit of time with Dian Wei, and his last stand to protect Cao Cao, while maybe not acted or Choreographed well, still manages to be fairly sad, even to the player who again, spent time getting to know him and play as him.
In Dynasty Warriors 7, you spend a lot of time with Xiahou Yuan, since he's with you from the very start of Wei's Campaign, you're getting to know him, and he lasts almost until the end. You see how carefree, and nice he is, he gets along with his soldiers and fellow officers well. And then You/Xiahou Yuan beat Huang Zhong, he's ordered to be taken in to custody, only for him to escape, and let loose an arrow (after Xiahou Yuan's bow breaks on him when he needed it the most). He falls over, closes his eyes with a peaceful smile and just asks. "...Where's the luck?" They way the line is delivered, the excellent song used here, and how well the player knew him. It's gut wrenching.
Cao Cao's passing in 7. He's ill in bed with Xiahou Dun telling him not to worry himself over matters. Cao Cao breaks his cold facade and thanks him for everything he's done for him and that his conquest is at an end and he can finally apologize to Dian Wei and Xiahou Yuan for laying down their lives for him. When Dun turns around he sees that Cao Cao has died.
Becomes Harsher in Hindsight if you're a fan of Wei; the next scene as you know with Cao Cao dead and his son Cao Pi passing away six years later, there's nothing stopping Sima Yi and his plans now (that is if you still view Sima Yi as the villain and not as someone who took over Wei for the greater good).
Guo Jia lamenting his lack of life whenever he's not being The Hedonist is rather sad to see.
Guo Jia: I don't have very long left. This is perhaps the first time I've ever regretted that fact.
It was pretty heartwrenching in some Legend Stages though, in particular Ding Feng's... He recalled the time when everyone he knew was alive and the scene was very cheery... but then cut to present and it's a snowy night in Dong Xing, and only Lianshi was around (it's gotten lonely), while Wu at the moment were filled with talentless hacks like Zhuge Ke. And despite knowing that they'd fall with those people, the only path for Ding Feng is just to move forward for the dead...
Even earlier than that, there is a very sad scene in DW5XL, when defeating Ma Chao at Jia Meng Gate. Even though the games certainly don't shy away from his history, it's then that it becomes very clear, after all the crap he's gone through (even if some of itwas his own fault), how badly it's hitting the poor guy.
Ma Chao: My family...my friends...my homeland...all has been stolen from me. And now I lose again. Am I so weak?...Is there nothing I can protect...?
Made a bit better by the fact that Liu Bei took him into his ranks after the battle. Zhang Fei, Wei Yan and Zhuge Liang all have their own touching speeches (especially Zhuge Liang's) to give him just after Ma Chao's quote.
DW5's version of Yiling had several heart-aching interactions between Sun Shangxiang and Liu Bei, especially since before 6, they were on opposing sides. Sun Shangxiang's ending in the said installment while it wasn't even akin to her suicide in the novel, is just as damn sad.
Dynasty Warriors 7 Empires allows you to become sworn siblings with, or marry, other characters. If your sworn sibling or spouse dies in the same battle you are participating in, you are made to see an event where you rush to your ally's side, only for them to die in your arms...
All of Pang Tong's death scenes in every game he's featured in. 5 was probably the best, where he has a message to Zhuge Liang:
"Zhuge Liang, tell me... if I... were a... dragon too... would I have... flown... higher?"
While most, if not all of the bonus stages in 8:XL are hilarious, Shu's "Find Red Hare" stage takes a surprisingly somber turn when the identity of the horse thief is discovered. It's Lu Lingqi, and she "stole" Red Hare because she was desperate to have something to remember her father, Lu Bu, by. With Xiapi fallen and all of his soldiers either dead or defected, Red Hare is all that remains of her father's once proud legacy. She practically begs the Shu officers to let her go, but they have none of it.
A tear jerker that could overlap with Fridge Brilliance is suggested by one joshscorcher in his 'Top Ten Dynasty Warriors' video in regards to Liu Shan. The smile he almost constantly has? It seems forced. Joshscorcher's idea is that Liu Shan is unhappy with being a ruler and hates the chaos and the fighting, but because his father was Liu Bei, he's weighed down with chains of duty and expectation. Not to mention his father is a tough act to follow.
9 levels up his turmoil where after calling out on Jiang Wei for his futile campaign in the north, Liu Shan sighs that his officers are fighting on a hopeless war where many people will keep on dying and confides to Xingcai that their kingdom remains driven on an outdated dream. The sad part is that he cannot explain to them properly about this.
Wen Yang's victory line when defeating an officer is 'Are there no heroes left in this land?' When you think about the time he was an active officer, no there really wasn't any left. The great heroes that were under the Sun family, Liu Bei and Cao Cao are by this time long dead, Wu a mere shadow of its former self and the talented officers they have left, like Lu Kang, were too few in numbers. Shu meanwhile cannot even be considered a danger anymore and their repeated attempts and failure to defeat Wei by this point almost seems more of an annoyance to Wei more than anything.
Jin ending in 7, at a banquet held after Wei has conquered Shu, as the Wei officers are celebrating and boasting while they feast whilst those who represent Shu are in a somber mood when music is played and The men of Shu there hear it and smile as they recognize it as a song of their home and country and cannot help but weep over what has happened. They maybe the same generic Non Player Characters that you see all the time but they feel pain and despair at what has happened
Zhuge Liang's second to last cutscene in his story mode in 6. The battle for control of the land between Shu and Wei is set to be at Wu Zhang Plains. On the surface it appears that Zhuge Liang is fine and has made a master plan but once he is alone he stumbles and coughs bringing a hand to his chest in pain and his voice changes as he pleads with his body, begging it to keep going, for just one more battle so that he can end the wars at last.
Worse? This is nearly exactly how he died in the novel-all the work and stress from planning that was all heaped onto him ended up killing him, and he died watching over the battlefield one last time while his troops burst into tears.
Sima Shiís death in 8. He dropped into his younger brotherís arms and tearfully told him that heíll be in charge now. Sima Zhao didnít take it very well because he knew that he might not be the right person up to the task and tried to tell him not to leave him. Thereís also Zhuge Danís response where heís on his knees, crying which is sadder later on when he rebelled against Zhao in the historical route.
In 9, Zhao blames himself for his brother's injury which he got at the Battle of Mt. Tielong while escaping. When Shi is at his deathbed, Zhao apologizes for what had happened to him but Shi reassures to him that it's all right and tells that he's in charge now. As his brother dies, Zhao breaks down as he calls out his brother. Compared to the previous games, this game shows how close the two Sima brothers are and how Shi's death affected Zhao.
The last part of the credits in the historical routes in 8 showed the characters who have died in the game: Dian Wei and Guo Jia of Wei; Sun Jian, Sun Ce, Zhou Yu and Lu Su of Wu, Pang Tong of Shunote Oddly enough, Guan Yu, Guan Ping and Zhang Fei would have been included and Guo Huai, Sima Shi, Zhuge Dan and Xiahou Ba of Jin. Of course, you can prevent all these deaths which would led to the hypothetical routes.
Liu Bei's death in 9 has him reminiscing the good old days where he, Guan Yu, Zhang Fei and even Sun Shangxiang were traveling around and then, he starts to cough. Sun Shangxiang drops the tray that she's bringing and rushes to her husband's side. As Liu Bei dies, Sun Shangxiang closes his eyes and mourns for him with Zhao Yun while Zhuge Liang looks up, trying to hold the tears.
The Battle of Yiling in Wu's storyline in 9 is actually Pyrrhic Victory for them. While they did managed to defeat Liu Bei, Gan Ning is fatally injured much to Ling Tong's shock who begs him not to die. As Gan Ning apologizes for killing Ling Tong's father and dies, Ling Tong breaks down into tears while Sun Quan watches and quietly apologizes to them. Then, the next cutscene shows Sun Quan visiting the Sun family grave and dropping down to his knees as he tearfully begs his father, brother and all of his retainers who have died on what he should do.
Considering that Ling Tong hated Gan Ning for killing his father in the first place, these two slowly got rid of their old grudges and became friends. Gan Ning's death and Ling Tong's tearful reaction to it shows how deep their friendship is.
Dynasty Warriors 9 went back to the individual-driven stories where each of the 90 characters have different endings. Let's just say not everyone have happy endings:
In Liu Shan's ending, the people of Shu are sadden and furious of his surrender to Sima Zhao that they even throw stones at his carriage and call him a failure to his father. Inside the carriage, Xingcai notices that Liu Shan keeps clenching his fist until it bleeds which shows that he is deeply hurt because of his failures and has to bear all the anger and hatred by himself, much to Xingcai's sadness. In contrast to the previous games, this game is the only time where Liu Shan openly shows his emotions.
Diaochan's ending has her deciding that she cannot be with Lu Bu and says her goodbye to him. She knows that she will bring him down because she is the poison to many men's hearts. Lu Bu accepts it and tells her to live on as herself not as poison or her father's pawn. After Lu Bu left, Diaochan thanks him and vows that she will continue to have him in her heart. Usually in most games, she would follow Lu Bu towards the ends of the earth. But here? She makes a painful decision not follow the man that she love and respect.
In Xu Shu's ending, he becomes a vassal of Wei but he's not satisfied with his new way of life as his rank in court is very low. When he heard that Zhuge Liang became Prime Minister of Shu, Xu Shu is very jealous that he might not live up to his former friend and begins to regret his choice of not serving Liu Bei. Unbeknownst to him, Zhuge Liang actually honors him. Too bad Xu Shu never knew this.
Guan Yu's ending is the start of the Battle of Fan Castle. While making preparation and looking at his children, he vows that he would guard the land for his sworn brother and holds his spear up in the air. Then, the scene turns grey which slowly pans to his spear-riddled corpse and fades into black with Guan Yu weakly whispering, "Brother".
Zhuge Liang's ending is his impeding death at the Battle of Wuzhang Plains where he oversees the battlefield on top of the mountains. After he bestows Jiang Wei as his successor, he quietly passes away and is greeted by the spirits of the three oath brothers.
Cao Cao's ending also features his impeding death (albeit offscreen). After giving orders to let Liu Bei and Sun Quan fight each other in retaliation for Guan Yu's death, Cao Cao starts to feel unwell much to Xiahou Dun's concern. Upon his death, his son Cao Pi reads his last instructions to not to hold any public funerals for him and let the officers continue their duty. Then, Xu Chu is crying out to the sky and Cao Xiu drops to his knees, shaken with the loss of his uncle. The rest of the Wei officers are bowing their heads with grief and shaking their heads with disbelief while the soldiers and civilians join in the mourning. Then, Xiahou Dun asks forgiveness to his late cousin that he and rest of Wei soldiers give their final salute to him. This ending really shows how the people of Wei really have respect for Cao Cao.
Dian Wei's ending is the aftermath of his death where Cao Cao, Xiahou Dun, Xiahou Yuan and Xu Chu are mourning for him and drinking. Seeing the empty chair beside him, Cao Cao couldn't take it anymore so, he stands up and looks at the sky. He remembers Dian Wei's Heroic Sacrifice and vows that he wouldn't forget him.
Wei Yan's ending happens when he heard of Zhuge Liang's death and feels that all hope is lost after Liu Bei and Zhuge Liang are gone. Despite Ma Dai's efforts to calm him down, Wei Yan rushes into the battlefield towards the enemy base. If you read history, the Battle of Wuzhang Plains is the last time we heard of Wei Yan and Ma Dai is going to kill him for disobeying Zhuge Liang's last order which is to pull back and retreat.
Xin Xianying witnessed her father expiring right in front of her and the Perpetual Smiler ends up sobbing. When compared with other ladies whose endings were at least either peaceful or happy ([not counting the downer future later), Xianying is the only female character who got a downright sad ending.