TL;DR: Midnight Masquerade

This is an experimental post to supplement a TL;DR of an OC's backstory over the course of the many fics they've appeared in (as well as the implicit links between them). As such, spoilers may appear below, tagged by story. All fics that are not rated M will be linked as well.

Name: Midnight Masquerade
Aliases: Shadow Beast, Foresight, The Cyclops
Status: Alive, ~2000 years old
Species: Changeling
Gender: Male
Stories: Changeling Chronicles, The Unforeseen, The Crystal's Shadow, With Wretched Fangs, Project DYES, Wretched Hive 2 and 3, The Unseen

TL;DR:
[Changeling Chronicles] "Shadow Beast" is a reformed changeling that was discovered shortly after the Canterlot Invasion. He does not remember his true identity and seeks it out. He travels to a changeling hive in the dragon kingdom, where its queen tells him his true name: Midnight Masquerade. With the name comes the memories of horrific things he had done to the ponies in his past. He attempts to take his life but is saved and supported by his pony friends, especially a pegasus named Thunder Sword.

Back in Canterlot, he makes friends with a green pegasus named Hunter. They take an archery class together and the sessions end up postponed as another changeling invasion is underway. The hive that Midnight had traveled to had conspired against him and Equestria. He fights with the ponies against the invaders. Hunter is taken by them and turned into a changeling. This almost ends their friendship. Hunter and Midnight team up against the oncoming swarm. Midnight trots away with a permanent hole in his disguise right over his eye, and Hunter loses his horn which traps him permanently in pony form. Hunter ends up joining a more daring branch of the military while Midnight goes his own way...

[HEAVILY IMPLIED] Midnight had made a strange enemy during the invasion: A changeling named Foresight that seemed to know a bit too much about him. Foresight calls Midnight out of hiding in Equestria when the Crystal Empire suddenly emerges from exile. Together, they traverse the dark stairs toward Sombra's Crystal Door. Foresight reveals then that he is actually Midnight Masquerade as well. And that he is a failed attempt to truly right their wrongs. He opens the door to 1000 years ago, when Midnight was turned into a changeling. Midnight goes through to wipe himself from history. He fails due to an overly friendly changeling named Mercy chasing him down and stopping him. Unsure of their intentions, Midnight kills Mercy. Their intentions out in the open, Midnight is haunted by his actions and fails to carry out the plan.

[REDACTED] Midnight finds his past self, but his kill-hungry hooves are stopped when [REDACTED] Midnight runs away to the Griffin Kingdom to try to forget about his duty to uphold, as he is now haunted by both Mercy and [REDACTED]. There, he becomes "the Cyclops," an overqualified assassin for a shady syndicate seeking to take over the kingdom. But once he is found to be a changeling, he is beaten within an inch of his life. Midnight has known healing magic, so he gets better. He also decides that maybe his duties aren't the worst thing ever. He travels back to the dragon kingdom where the hive is.

[HEAVILY IMPLIED] Midnight discovers a group of deranged and mutilated changelings outside of the hive. They have good core values, though, so he decides to help them out. He teaches them healing spells, which help them survive their war with the main hive. Despite the words of the leader of these outcasts, Midnight leaves them to rejoin the actual hive, as that's how he will meet himself in the future. One of the outcasts comes with him, hoping to join a different rogue sect of changelings that like to take dragon forms.

[With Wretched Fangs] Midnight returns to the hive at the expense of one of the queen's most faithful servants. The queen sends the servant, whom she didn't like anyways, away and keeps Midnight as a neat little trophy of her victory over the wretched outcasts. And, of course, the queen calls Midnight "Foresight."

[Wretched Hive 2](M-RATING NO LINK) Foresight is used by the outcasts to coordinate changeling kidnapping efforts to help the outcasts divide, conquer, and survive. The changelings catch on and start using countermeasures to keep Foresight's "friend" from taking them. Foresight is forced into action when the ignorant changelings begin exploring Equestria and kidnapping a group of citizens. He even stands up to his "friend" when she tries to take them as well. The "friend" doesn't take kindly to this and destroys Foresight. Foresight is revived by the leader of the outcasts upon the "friend's" defeat. In his revival, his original form is restored. His disguises are no longer plagued by that bothersome hole.

[Wretched Hive 3](M-RATING NO LINK) Foresight decides to cut all ties to the outcasts. But something pulls his dreams back to them. Worried that something might be trying to kill off his former friends, Foresight investigates the disturbances. Unfortunately, his own twisted nature and haunted past blind him to the true forces at hand. Defeated, he burns all bridges connecting him with the outcasts. He is Foresight, after all. He doesn't want morals and friendships getting in the way.

[The Unforeseen] Feeling more and more lonely and missing his old friends, Foresight saves the life of a misfit drone. The drone attaches itself to Foresight. The two grow closer. Then the queen names his new friend Mercy. Foresight tries to burn the bridge but fails. Things only get more complicated when the queen's biggest fan returns from exile. Her name is Vertigo, and she seems to understand Foresight better than anyone. She helps keep Foresight and Mercy together, despite Foresight's wishes. In the end, Foresight pushes Mercy as far away as possible before joining Midnight in the Crystal Empire. He sets the cycle to go right this time, only to have Mercy show up to save him. Mercy follows Midnight through the door. Thoroughly sick of his uselessness, Foresight opens Sombra's Door to the dark trap side. The darkness consumes Foresight and destroys him.

[HEAVILY IMPLIED] King Sombra is defeated and with the surge of love coursing through the castle, Midnight is revived. His eyes, mind, and body are weakened by the door's effects. Traveling outside, his memories slowly return and he realized that Vertigo died trying to save him as well. The grief sends him into a fugue state.

[The Crystal's Shadow] A crystal pony is depressed and he doesn't know why. Then he learns that there's a changeling in the upstairs bedroom. Then he learns that it's just a mirror. Upon accepting his identity, Midnight reawakens and decides to return to Canterlot after 1000 years of being a slave to his past.

[HEAVILY IMPLIED] Discord is reformed, which gives Celestia a good idea. She gives Midnight the sole responsibility of tracking down and reforming rogue changelings.

[Project DYES] Midnight Masquerade tracks down countless changelings that he used to know from the hive. Unfortunately, Chrysalis had made everyone hate him. The only changelings who really cared about him enough were Mercy and Vertigo. Mercy was dead about 1000 years ago, but Vertigo was fresh. Using the outcast's resurrection magic, Midnight brings her back to life. Happy with himself, he seeks to dissolve the whole endeavor despite two recruits joining him: Desert Mirage and Thunder Sword. Thunder Sword saved his life back in Changeling Chronicles. Desert was a new face. Vertigo joins the team later as "Gravity," a name she earned for herself in the griffin kingdom.

Lots of stuff happens in Project DYES, so I'll keep to the stuff that matters most to Midnight: The outcasts reappear. They are too disgusting to be allowed to join Equestria. Midnight stokes the still burning bridges. As the situation turns dire for the outcasts, they bring the "friend" from Wretched Hive 2 back. Her name is Elegiac (Elly is a lot easier to pronounce). Elly and Midnight hit it off now that she's not as rabid and bloodthirsty as she used to be. He eventually finds a kind of new hope in her, which keeps him fighting. Unfortunately, she sustains major injuries and is put into almost dead state. Midnight still has her to talk to, but another resurrection ritual will be needed to bring her back completely. The same can't be said for the rest of the outcasts. But Midnight's company seems to be working, and more changelings are found and reformed.

The end?

Note: [The Unseen] is an AU fic so it's not actually part of Midnight's backstory at all. At this point, it kinda contradicts actual canon as well, so I'm just going to leave it alone.

IF YOU LIKED THIS, please tell me and I'll keep this post updated as more fics are written. Feel free to comment ANY OC that I've ever written on that you'd like a TL;DR for. Midnight is my main OC so he's been in all but one of my stories so far. I figured it was a good place to start.