These are what we call the 'YMMV items.' Things that some people find in this work. We call them 'your mileage might vary' because not everyone sees these things in the same way. This starts discussions in the trope lists, a thing we don't want. Please use the discussion page if you'd like to discuss any of these items.
YMMV: Twilight Then Twilight Now Universe
Base Breaker: The story is this taking the franchise fandom into account. It gets any number of reactions to mainline Bronies, but My Little Pony Tales, My Little Pony G1, and My Little Pony G3 fans tend to react negatively to the fic, be it making the G1 portion a shadow of Equestria, Tales into a a Nightmare Fuel society at it's core with racism and mutilation, responsible for spreading the Fannon-only term Coltenville from this fic to those that aren't aware the setting wasn't known as this, and other unfortunate slips into trying to unify all the series, even if the author meant well.
Ron the Death Eater: Played with. In Moondancer's Misguided Mission, Sun Shimmer (the recently hired assistant teacher from Mustangia) is doing this to Celestia and humans (such as Megan). Word of God says that this is a direct reference to the general fandom view towards Celestia and when putting humans in the FIM universe (especially the Solar Empire vs. The New Lunar Republic and ''The Conversion Bureau'').
Complete Monster: Face it, you have to be one to do what Sunset Shimmer did to her daughter without remorse.