The Defeated
What if the heroes (or the occasional villains) were defeated.
Chapter 1
by 
Unknown7
All characters in this story are at least 18 years old.
The Watcher, Asmodatu, appears to us on an alien landscape.
"I am Asmodatu the Watcher" he told us, "like Uatu, I have observed the rise and fall of civilisations, worlds, galaxies. I know all that is, most of what has been and much of what will be. I also have many windows into the strange parallel worlds of what might have been"
Asmodatu waved his hand and showed an image of Rey's lightsaber duel with Kylo Ren in Star Wars: The Awakens.
"In the reality you know, Rey defeated Kylo Ten in their first duel"
Asmodatu showed us the chasm splitting between Rey and Kylo.
"But what if..." said Asmodatu.
Asmodatu showed an image of the fight again but this time Rey was on her knees with Kylo Ren holding his lightsaber to her neck.
"In other worlds" Asmodatu explained, "Rey was not so fortunate. Here she lost her duel to Kylo Ren. And there is more"
Asmodatu then showed an image of Rey in Snoke's throne room with the Praetorian guards standing over her about to strike.
This was followed by an image of Rey sitting on Palpatine's throne. She was wearing dark robes and her skin had gone grey similar to Palpatine. Ben Solo stood in front of her, wearing Jedi robes.
"And even worlds where Rey never made it off Jakku at all" said Asmodatu.
Asmodatu showed up an image of Rey naked and tied to a whipping post. Unkar Plutt stood behind her, holding a whip. Asmodatu waved his hand and the image disappeared.
"For every reality where the heroes win" he said, "there are countless where they lost"
Asmodatu showed images of Agent M from Men in Black: International being by aliens, Bella Swan knelt down naked and in chains in some Volturi dungeon, and Mary Jane Watson being carried off by the Green Goblin on his glider as Spider-Man lay on the ground, defeated.
"But it is not just heroes these misfortunes happen to" Asmodatu said, "in many worlds, villains also suffer misfortunes that never happened in what you call canon"
Asmodatu showed an image of Esdeath from Akame Ga Kill naked and at the mercy of Night Raid. Again the image disappeared.
"Now it time for you to explore the wonders of the multiverse" said Asmodatu, "inside each world, you will have a victim. You get to decide how their downfall happens or maybe even save them from their fate, if you so choose"