This started on a random doc on how Luna turned into Nightmare Moon because when I was planning my other fic Growing in Time I thought a LOT about it.

The idea that Luna, the element of LOYALTY, betrayed her sister? What fun thing to chew on. Did Celestia see it coming or was she shocked? Was it a slow betrayal or sudden?

So yeah this is how I thought it went down, seemly slow but sudden to Celestia and her alone tbh

PS this does take place in the same AU as Growing in Time which is why the timeline won't make sense if you try and place it in canon. You don't have to read GiT for it to make sense (because I haven't gotten that far )