Fan Works / Angsty Surviving Twin

In chapter 56 of Kyon: Big Damn Hero, Tsuruya's Ninja Maid Shinobu tells Kyon how she used to be a women's rights activist in her youth who made powerful enemies that killed her sister in a Revenge by Proxy. Said sister was Tsuruya's mother.

In the unfinished 9U Fanfiction by Jenny-Jen on Deviantart, the stitchpunk 23 loses her brother 24, after his soul was sucked into a machine, the manner of how he died was at the hands of 25, a stitchpunk who decided to team up with the machines to suck out all the souls.

Danganronpa: Darkened Hope: Daichi's death in Chapter 1 shakes Kat to her core, permanently altering her character and paving the way for most of her character development. The trope name is a bit misleading, though, as Daichi and Kat aren't twins. (Daichi is roughly a year older.)

Vow of Nudity: Ni-bast's backstory. She sold her soul to a devil to get her twin sister invulnerable armor when she went off to war, but the armor only made her a high-profile target and ultimately got her killed. Doesn't become fully clear until her second appearance, when she refuses to help Haara subvert a prophesy because of her belief that You Can't Fight Fate and doing so only leads to terrible consequences.

Vanna is this Alternate Universe Fic, Something Always Remains. Her twin sister, Vesper, disappeared at Fredbear's when the two were four years old, and her mother tried to make Vanna forget it ever happened. Done again when it's later revealed that Vanna's mother lost her own twin sister in a different Fredbear's accident, and after the disappearance of her daughter, was completely done with the restaurant.

Percy is revealed to be one in The Awakening of a Magus, due to a powerful twin bond breaking when his brother died the day after they were born.

A Thing of Vikings: During Sigurd's trip south to the Roman Empire, the trade caravan he's part of gets attacked by raiders. Thanks to him and Hookfang, his people mostly get through unscathed, but one of the guards, Ondott, gets killed because he didn't see the horse-archers coming, due to Hookfang blocking the line of sight. His twin brother, Kormak, blames Sigurd for his loss, not seeming to care or even be able to acknowledge that things would have been worse if not for Sigurd.

Dreaming of Sunshine:
- Tsunade brings this up after the Retrieval Arc - Ukon dies after trying to possess Naruto, leaving his twin brother Sakon to be brought back to the village for interrogation.
- Also, Toki in the Land of Birds Arc.
- The fear of this trope is what drives some of the interpersonal conflict between Shikamaru and Shikako - with Shikako near constantly in danger, Shikamaru fears losing her.

Prince James is one of these in Once Upon a Time and Again, as his elder twin brother David died before the beginning of the story. In canon, they had never met before James was called in as a Backup Twin and Spare to the Throne.

Throw Away Your Mask: Implied to be the case with Minato. He had a sister, and Theodore says the guest he was supposed to attend died when she was young, suggesting that the female protagonist^note existed but died in the Moonlight Bridge accident. She's never named, but Minato talks about her sometimes, like when he suggests building sandcastles at Yakushima or when explaining his hesitation over not killing Ryoji.

Since Subway Boss Ingo appears as an amnesiac stranded several hundred years in the past in Pokémon Legends: Arceus, it's common for fanfic writers to show his twin brother Emmet coping with the loss of his brother.

In A Sword to Pass, Ursa’s rather jaded few of Jedi, and her displeasure of Ezra’s close relationship with her daughter, comes from a Jedi killing her twin sister.

In Jimmy's Visit With Dr. Franklin Johnny, Jimmy's twin brother died due to the immense torture Ebon put him through and Jimmy had always blamed himself for his death.

The Tales of the Abyss fanfic Reflections has this brought up or alluded to in regards to Asch and Luke though they aren't twins but original and replica, functionally they have acted as such since Luke joined the family, and the Big Bad wants to invoke this to get Asch under his control.

In the Better Bones AU, Dove's Wing deeply grieves the death of her littermate Jay's Wing while fighting Hollyleaf, and renames herself Half Moon in part due to feeling split in half by his death.

Angsty Surviving Twin / Fan Works