It’s been four months but I have a few things to address.Except that Chrysalisaccount for aura color; her aura was still a distinctive poison green while she was impersonating Cadance, who has a gentler cyan aura. Twilight Sparkle, magical genius nonpareil and audience of Cadance’s lovey-dovey magic during the foalsitting years, personally witnesses Chrysalis’s magic — and her deduction is that Cadance has turned evil, not that Cadance is being impersonated.Twilight even tries to murder her when she sees the real Cadance, the thought of two Cadances never having occurred to her until that moment.If Twilight had been able to see aura color, she would have noticed it was the wrong one. So would Celestia or anyone else who knew Cadance more than passingly, for that matter.I don’t need to say a word to feel smarter than these kinds of people.Well of course Rarity would notice that her own magic wasn’t behaving properly, regardless of whether she knew what color it was or not. The aura color fizzles so that the viewer immediately understands this. How would you explain an invisible condition to a kid within 1 second?Does Sweetie Belle actually go through the motions of "figuring out" that there’s magic in that scene, or does she simply know / immediately accuse her? Because Sweetie is super-savvy to Rarity’s nonsense; she doesn’t need to see or feel magic to know her sister’s being sneaky. Rarity has one of the worst poker faces in the show.