"Spike." Applejack slowly turned her head. "I have something to tell you."
"Hm?"
"I'm Twilight."
Spike blinked, taking another bite out of the grapefruit in his claws. Yes, with the peel on.
"I'm serious, Spike. And so is Fluttershy, and Rainbow, and every other pony here in Equestria."
Spike swallowed the rest of the grapefruit. "Alright, Applejack, let's take you to Nurse Redheart."
"But Nurse Redheart is also Twilight," the aforementioned mare stepped up behind Spike.
"Oooooo-kay then, how about we go to Zeco--"
"She isn't me," Applejack and Nurse Redheart droned in unison. "She was not here during the incident."
Celestia landed between the three with a heavy whumph. Splaying her wings out, she declared in all her glory...
"I too, am Twilight."
"TWIIIIIIIIIIIIIIII--" Spike bolted off, "TWILIGHT! EVERYONE'S ACTING WEIRD ALL OF A SUDDEN!"
"Twilight!" Spike kicked the door down. "Twilight, why are ponies saying that they're you?"
Twilight didn't budge from the chair she sat in.
"...Twilight?"
"I'm so, so sorry, Spike. They're telling the truth."
"Wh--"
"They're all gone. They've been gone for years now."
"Twilight--" Spike stepped over the remains of the door he'd kicked open. "--what are you even talking about? I was just talking with Applejack earlier! What do you mean they're gone?"
Twilight turned her head to Spike, tears streaming down her face. "Never underestimate the power of a book on vocal impressions, Spike."
"When Tirek took all the magic. Do you remember that?"
Spike gave a singular nod.
"It wasn't just magic that he drained from their bodies. Even after their magic was restored, ponies began to drop left and right. They still breathed; their bodies were perfectly fine--but their minds?"
Twilight pointed a hoof to her horn. "Gone with the magic. It came slow at first, with ponies forgetting things left and right, but eventually, they too would become husks of their former selves. They all live within me now. Or at least, they try to. When we stripped Tirek of the power he stole, there were some... unintended side-effects. Every pony you see out there today--those are puppets. Bodies I control to give them at least a semblance of their past lives."
She lowered her hoof.
"I am the last pony in Equestria, Spike."