Skaterloo meets Nyx from Past Sins
 
Skaterloo: What are you talking ‘Princess Twilight Sparkle is my mom’ that’s MY mom’s name I don’t have a sister!
 
Nyx: Well I don’t have a brother and why do you just look like Scootaloo as a colt and have her Cutie Mark?
 
Skaterloo: Who is Scootaloo and what do you mean have her Cutie Mark the only other ponies with a Cutie Mark like mine are Apple Bloom and Sweetie Belle. And why do YOU look like Nightmare Moon!
 
Nyx: Scootaloo is the pegasus filly in the Cutie Mark Crusaders and I’m an incomplete clone of Nightmare Moon.
 
Skaterloo: I’M the pegasus member of the Cutie Mark Crusaders! Get out of my mom’s castle!
 
Nyx: This MY mom’s castle you get out!
 
Skaterloo: You get out!
 
Nyx: No you!
 
Skaterloo: YOU!
 
One of them has entered an alternate universe question is which one?