>>42282781
Pinkie Pie is secretly pulling the strings behind everything.
After temporarily gaining Discord's chaos magic, she sent her consciousness back in time to when she obtained her cutie mark.
She then repeated this process numerous times, being able to carry over more and more of her chaos magic each time she did a time loop.
She would gain multiple chaos abilities like Pinkie sense that would warn her about upcoming events kinda like knowledge from the future but more of a body warning rather than knowing it from memory. To put it simply, she just knows without knowing.
She then uses all this body information gathered to effectively turn Ponyville into a utopia by making every single pony happy.
It is theorized that if she loops enough times, she will become a god of chaos like Discord and basically become unstoppable.
Her morals may deteriorate from the power going to her head and it will eventually lead to her trying to make the whole world a utopia of smiles through any means necessary.
Also the mirror pool does not clone ponies, it is actually a portal to other timelines/dimensions.
Pinkie will constantly swap places with other Pinkies from other timelines without anyone noticing.
No pony is safe from Pinkie Pie, we are all doomed.