If they bring in a pony equivalent of Hades, I wonder if they'll have fun with the
Everybody Hates Hades trope!
I bet in season 3, they'll have an episode where everypony becomes paranoid over Changelings, and wondering if there are any among them, and if so, who.
I can imagine ponies pointing hooves at Pinkie Pie, because she's eccentric, and the eccentric ones always get the blame when something goes wrong.
I bet Bon Bon will turn out to be a Changeling, because she acted like an unmitigated
Jerkass several times, and told Rarity to her face that she never heard of her. I bet a Changeling would never have heard of Rarity!
I can also imagine Diamond Tiara accusing Apple Bloom of being a Changeling right in the middle of class. Why? Because DT has an irrational grudge against the Apple family, and she's using Changelings as an excuse to ruin them. Plus, the Apple family is pretty large, and Changelings could easily blend in with a crowd. Then, you'd have the Cutie Mark Crusaders wondering if DT is a Changeling, but they decide to try to find evidence before they throw any accusations at
her.
Maybe an episode like that wouldn't happen, but it would be interesting if it did!