I’ve already talked about Opaline’s backstory and why I’m not feeling the whole “is as old as celestia and luna” thing, sooo… Rewrite, anyone?

Twilight was feeling pretty confident. She’d successfully trained Starlight Glimmer in the ways of friendship years ago now and, she had to admit, she was missing teaching. So, she took Starlight’s daughter Luster Dawn under her wing. But, as Luster Dawn was doubting the worth of Friendship, Twilight had an idea: taking a new mare- Opaline Arcana- from Celestia’s School for Gifted Unicorns under her wing as well so that the two could work alongside each other to learn about Friendship in Ponyville. The two students became close, even reminding Twilight of the relationship between her and her brother when they were foals, and had a friendly rivalry to see which pony could become stronger faster. They both worked hard, both equally as eager to prove their worth to their mentor. Functional, healthy, perfect, Twilight was sure that she’d made the right choice.

It was one day when Luster Dawn seemed to be getting ahead of her in her studies that Opaline wanted to catch up. She wanted to show off to Twilight and Luster with something new, something nopony else had done, so she began her work. She went exploring in the Castle of the Two Sisters, hoping to find something the previous rulers had left behind that she could learn from… And she found it: Princess Luna’s old diary. Opaline managed to figure out that the last page was somewhere before Luna became Nightmare Moon, and so she began to read through. Her gut told her this was a bad idea, but her determination to show up her rival prevailed. It can’t be that bad, right? As far as she knew, she had no negative emotions to feed off of like Luna did back then, so she’ll be fine! She can get a hold of whatever power Luna used!

She was wrong. She was so, so wrong.

The power consumed her, the spell that Luna used to transform- to turn her negative emotions into a new powerful transformation- it instead began sucking away all of Opaline’s positive feelings. Friendly rival became pure rival, a desire for knowledge became a desire for power, and a desire to stand by Twilight’s side became a desire to surpass her. This was a spell meant for a powerful alicorn, not a mere unicorn like Opaline was, so as wings of fire burst from her back, she was stuck.

Twilight and Luster tried their hardest to help Opaline- they really did- but nothing was working. Twilight had to do something, and despite Luster Dawn’s pleas against it, created the Unity Crystals to hold all of the magic in Equestria if Opaline ever tried to create rifts between the pony races again before locking Opaline’s magic away with only one way to return it to her.