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Tear Jerker: Shifting Worlds
SDM is a self-admitted "asshole writer", "sadistic dungeon master" and Troll who thrives on inducing reactions in his readers and their characters. One of his favorite tricks is to create developed, very likeable characters and then kill them off in sadistic ways, masterfully writing their death scenes to ensure that the death hits the players as hard as possible. The Hellgate saga teems with soul-crushing moments. What makes them so powerful is hard to describe... read them for yourself if so you wish. SDM eventually decides to weaponize his Tear Jerkers: in Hellgate 2 part 2 the ultimate attack of the Black Spawn is to force the characters to experience every painful moment in their lives, but especially in the Hellgate Saga, at once.
In the very first Hellgate roleplay, the one Tear Jerker that started it all: the death of Flandre of the future. Especially since two of the participants were Flandre fans.
Hellgate 2 Part 1 has the destruction of Eientei and all its inhabitants and the death of the unnamed rabbit girl. Both come off as definite Kick the Dog moments, but fail to receive enough development to be true Tear Jerkers. Also narrowly averted when the heroes manage to bring Hellgate down without having to kill off his power source Patchouli (unlike in the first Hellgate roleplay, where the power source was Future Flandre already mentioned above.)
To make up for this lack of Tear Jerkers in the previous part, Hellgate 2 Part 2 is VERY heavy on Tear Jerkers.
While not too developed, the death of the unnamed Infected youkai girl in the beginning is rather depressing, though it's nothing compared to the multitude of high-powered Tear Jerkers awaiting in Coronai.
Then we have Mia's crowning followed by the emotional death of King Gustaf. Even though the King does not get much screentime, he had been established as a highly competent and caring monarch and the scene is well-written enough to hurt. Made that much emotional by the use of this song.
And then as the Black Spawn comes we are treated to a series of those: the end of the Three Goddesses (Ami is the only one whose death we see, but it's more than enough). Then there's Zoruff's Heroic Sacrifice, and then, last but not least, the death of Mia, made that much worse by the fact that she dies with the feeling of having failed her kingdom and her father.
And then Hellgate 2 Part 3. Oh gosh, where to start...? First off, Gensokyo has been destroyed, along with the barrier separating Gensokyo from our world, which caused humans and youkai to invade each other's worlds. SDM and Aurion's family were kidnapped by The General having who-knows-what done to them. The ruins of Gensokyo, the homeland of everyone who wasn't part of the Rebellion at that time had to be abandoned, never to be rebuilt or repopulated. And that's all during only the beginning of the story!
The XAT sub-RP SDM leads is not without occasional heartwrenching moments:
Though nobody saw it coming, and though it was immediately replaced by a very similar alternate universe, there was obliteration of the entire universe the RP was originally set in at Anathemus' hands. Seriously. All the characters played up to that point, all the progress done, unmade by a dark god in a matter of seconds.
Post-Warped Realms: Executor is a great source of this. He decided to go against everything he held dear, become the leader of the Nihilus Clan and throw away his own life (with a multitude of other lives) just to give his three friends a shot at a "normal" life. Ever since, whenever he's not being an asshole, he is being tear-jerking.
Notable: to cement his reputation as a monster and distance his friends from him, he has to kill Princess Luna. However, he is not able to do it in cold blood, and actually ends up revealing his motives to her. And Princess Luna seems to understand him completely. Many tears were shed.
Luna: "If that is how you feel, then I will not resist. Spill my blood. For your friends."
Fluttershy's dark beast does well in exemplifying the hard dichotomy of either repressing anger or letting it all out. Moreso in that, in the end, no resolution for her problem was actually found, with not-so-subtle implications that there ISN'T a way to solve it.
Princess Celestia passes away in the finale of the Dark Beast arc, after having overcome Nihilius' sway over her and allowed his defeat possible. Prior to fading, she manages to congratulate the Factory and his agents on their success stopping Nihilius (even though this success came at the price of her own life). She also reminds them all to never give in to despair, and says that as long as they are united, they will surely overcome any obstacle. It's truly a speech worthy of PrincessCelestia and a fusion of Crowning Moment of Heartwarming and Tear Jerker at once. It helps that the music for her death scene is a piece appropriately titled Melting Sun, a remix of Rundas' battle theme (which was used as the soundtrack for her Dark Beast battle).
Celestia: "My final order... is for everyone to be happy... and if they are not... then never stop fighting until they are..."
Shortly after his death, Oneiros is heard whistling The Gypsy Bard - an outwardly cheerful song as befitting of a victory that guarantees the safety of Equestria... but listen to the lyrics again, will you?
When you've bungled all your bangles, and your loved ones have been mangled...
And shortly after that SDM wrote a solo story detailing Executor's death, from Executor's perspective. It was bad enough in-RP, well the story makes it a thousand times more emotional. Torrents of tears have been shed. The reactions of the player characters to his death - detailed in their own solos - are only a little less heartwrenching.
On Kanako's side in the same RP, it's not hard to feel for Lynna when she discovers that her existance is nothing but a fake created by Anathemus.
Shadow Ryusaki is not without his own occasional punches.
Poor Eli gets turned into a monstruosity by a Nirvana Shard and subsequently has to be killed. It helps that her demise mirrors Sayaka Miki's very closely.
King Cerus having to cast away Princess Ceilia, for the sake of everyone involved (since Ceilia is a living Nirvana shard, she tends to attract a lot of attention, and not of the good kind). Unfortunately, in order to get her to leave, he needs to say some very mean things to her...
In Crossroads 3:
The treatment Nilhem inflicts on Yuro and Tiffany in his prison for sub-humans.
The same Nilhem also massacres an organization of rebels who were trying to free those prisoners, and turns their leader into a monster which the group has to kill. Infuriatingly enough, he himself escapes.