There must have been other Zipporwhills. That was how the connection between their worlds worked, wasn’t it? So in Equestria there must have been a young, excitable filly with a bright smile and thick glasses and a dog named Ripley that she loved more than anything else in the world. Maybe she was a unicorn, or an earthpony, or a pegasus. Maybe she lived in Ponyville, or Cloudsdale, or Canterlot, or some small town she never would have heard of. Maybe even Sire’s Hollow, for all Starlight knew, for how little she visited. But no matter what, she knew that she would have had that dog named Ripley that she loved more than anything else in the world. And from the contours of her mind, she knew that she would have a cutie mark having something to do with dogs, and whatever about that made her feel fulfilled and happy she would have a lot of in her life, because that is how Equestria worked for ponies that weren’t broken like Starlight was.
And it was bad enough that she had that brokenness inside of her in the first place, but no, she had to go further than that. She had to take that brokenness and take it outside of her and spread it on others, convincing those poor, gullible ponies in that tiny town that they were broken just like she was and were better off without their cutie marks. But they weren’t, were they? That is what those townponies proved in the end, wasn’t it? That she was the only broken one out of any of them.
And it was bad enough that she had taken that brokenness outside of her and spread it on that tiny town of ponies, but no, she had to go further than that. Starlight Glimmer was the unicorn that wrote the spell that could remove the cutie mark of an Alicorn Princess.
Starlight Glimmer could do anything.
And of all the things she could have done with her talents and powers, she used them to take that brokenness inside of her and use it to break the entire world, with all of its millions of souls and lives and destinies and meanings that would have gone on to be just fine without her. Not just once. Not just twice. Over and over again, until that brokenness spread and spread and spread and turned the entire world into a bleak and empty wasteland where not even a single soul could live.
There must have been other Zipporwhills. Ones that did not get to live that carefree life full of meaning and love for that dog named Ripley that she loved more than anything else in the world. Ones that lived their entire lives having their bodies crushed under the weight of Sombra’s forced labor, their souls withered to listless husks by the feeding of Chrysalis’s Changelings, their dreams no refuge from the dread chill of Nightmare Moon’s eternal night, their sanity warped beyond comprehension by Discord’s chaotic realm.
There must have been other Zipporwhills, and everything bad that had ever happened to any of them was all Starlight's fault.