“Twiiiliiight?” the blue alicorn moaned.
“What is it, Dash?”
“I’m bored.”
“Well, sorry, but it’s taking me quite a lot of concentration to maintain this stability bubble.” Twilight flared her wings, slammed her forehooves onto the floor, and a magic circle bloomed out from her to five lengths in every direction. “There. Now, Dash, can’t you be at least a bit serious?”
“Why?” Rainbow Dash countered.
“We’re in the past. A long way in the past, in case you hadn’t noticed.” A raven shaped like a writing desk flapped past.
“I never was much of a fan of history.” Dash shrugged.
Twilight facehoofed. “I’d think even you would remember about how Discord was in charge before the Royal Sisters showed up.”
“Huh. So we’re that far back? Be neat to see what the Princesses looked like when they were younger.”
“No, you’re not getting it.” Twilight pointed from her to Dash. “We’re the Sisters this time. We’ve replaced Celestia and Luna.”
“…huh.” Dash absorbed that for a while. “Dibs on being Luna!”
“Why?”
“Twilight,” Dash said, as if talking to a filly. “Luna gets a thousand year nap.”
https://www.fimfiction.net/story/98568/3/mlp-time-loops/loops-3