It's always evil reformed to good, what about good becoming evil?

[cider float 2,536]

Why aren't there more villains that get reverse reformed? As in they start out good guys then become evil for some reason? Of course the villains that are reformed like Starlight or Luna could be considered "good" before but it was more in the lines of being innocent and not picking a side at the time.

[Arrowstormen 62]

Well, Sci-Twi became momentarily evil in Friendship Games, and there are tons of examples of the Mane Six being mean or "evil" for a bit in the slice of life episodes before learning the errors of their ways. That might not be what you were thinking of, but I doubt we will see any "good" recurring characters become evil and then not become good again at the end of the very same episode, or the episode after. 

[Castle Bleck 19,176]

I guess you could technically count Fluttershy in Putting Your Hoof Down, Rainbow Dash in Tanks For The Memories, etc.

 

Though they ultimately switched back, so...

[Singe 2,109]

Ponyville Confidential

 

They enjoyed reading the gossip on other ponies and didn't like it when it was their turn.

[takai 1,060]

I would say Luna turning into Nightmare Moon was a good example. She was consumed by jealousy and hate and that, plus that dark magic, transformed her into Nightmare Moon

Edited December 3, 2015 by takai

[Marimo 555]

 

 

Of course the villains that are reformed like Starlight or Luna could be considered "good" before but it was more in the lines of being innocent and not picking a side at the time.

 

Luna was definitely on the side of good beforehand. Discord, Sombra, Tirek, she helped to stop all of them.

[pony.colin 156]

@@takai, and @@Marimo,

 

Honestly to OP @@cider float,  Luna is the closest thing that what you want for face heel back to heel face turning.  

 

 

@@A.V., @@Singe,  - i can't agree with those, mainly because ... actually thinking about it, moral alignment doesn't really make sense too much in slice of life unless its made to be of certain obvious social situations.  Neither of the cases I would count as a case of "evil" or crossing over to the darkside, for Fluttershy in those episode (sometimes you have to be a little bit forceful, or show that you are serious to get a point and message across).  Ponyville confidential - well that's learning a social lesson.  Turns out if, you gossip about others, and you get found out as being gossiper, people will of course avoid and shun you for what you did. 

 

But like, yeah I agree with Marimo and Takai - Luna is the an actual as a good character becoming evilish then turning back to good, in regards to that alignment thing.

[Silver Stream. 708]

A lot has beat me to it, but Luna is probably one of the best examples when it comes to a good pony turning evil. And who's to count out Starlight Glimmer? She wasn't born evil.....in fact many of the minor/major antagonist seemed to have been good at one point until a turn of events made them go bad. 

[Kyoshi Frost Wolf 40,386]

Luna is a good example as others have mentioned, though I can see why you would want something a bit more substantial. Luna was good then became evil, but we never really got to see that progression. It would be really interesting if over an entire season, a character gradually become evil in one way or another, then they could be reformed after that. That would make for a very interesting season arch.