I was never fully satisfied with Flurry Heart or her design, so I tried to do some headcanons on her a long time ago to get into the spirit of alicorn babies. And now that I'm developing my Sugarverse more, I wanted to do something different with Flurry. I've seen a bunch of amazing artists draw Flurry Heart as a changeling, and it made so much sense to me. So now I'm hoping on the changeling bandwagon, here we go!
During Chrysalis' infiltration of Canterlot under the guise of Princess Cadence, she spent quite a bit of intimate time with Shining Armor. Her actions never went without reason, this one being more important to her than taking over the city itself. It was time for her to create a royal clutch (which she was only able to do once in a blue moon) and while Shining Armor was a pony, he was a very powerful pureblood unicorn. That and the strong love he felt towards Cadence made him the perfect target for Queen Chrysalis. She laid her royal clutch in secret, hiding them well in the caves beneath Canterlot, which were the same caves Cadence had been trapped in. Cadence was unaware of their presence, too busy trying to find a way out to see the eggs.
Once the changelings had been been expelled from Canterlot (leaving a good portion of their hive dead or injured by the magical blast), royal guards and the princesses made sure to rid the city of every last trace of the siege. One of the last places checked was the caves under the castle, where Cadence had refused to go until she could build up the courage to face the trauma of Chrysalis kidnapping her. When they did go with a small elite group of royal guard, they discovered the royal clutch and (under Shining Armor's rash orders) began to destroy the eggs one by one to avoid any more changelings in Canterlot. But before they could all be smashed, one started to crack open and hatch, leaving the guards and royalty standing defensively over the dark grub. But in a moment of empathy for the helpless little creature, Cadence rushes to stop her husband, having looked into the baby's gaze and seeing Shining's bright blue eyes staring back at her, showing no hint of malice. Shining Armor is more than prepared to end the nightmare right there and then, wanting to forget all about Chrysalis' deception to him and not wanting his wife to think that he chose to be close to the Queen Changeling.
Much to Shining's surprise, Cadence refuses to allow the extermination of the baby changeling and asks for him to give the grub a chance. And even with the stallion's extreme hesitation and Princess Celestia and Luna's blessing (albeit a wary one), Cadence begins to take care of the child in secret. As the Princess of Love, she had a seemingly never-ending amount of compassion for the baby, hoping that by showing Shining Armor how harmless and sweet the grub could be would also lead her to feeling less fearful of the child herself. Shining couldn't believe how hard Cadence was trying and eventually he fell in love with his daughter, even though he initially struggled to admit it. The two decided to adopt the child as their own, after an abundance of hard thinking and debating back and forth, and only then did they tell others about the baby. Or rather, Cadence announced "we're going to have a baby" while being very careful of her wording. They WERE going to have a baby, as soon as she was recognized and adopted. Just like Celestia and Luna, the Mane Six were absolutely flabbergasted by their choice. But it was their choice to make, and everyone made sure to let the couple know that they supported them no matter what. Shining Armor wanted to name her Persephone, which seemed rather dark to name her "Bringer of Destruction", but he assured Cadence it was dark humor with plenty of love mixed in. She was his little ball of potential destruction, and Cadence couldn't say no to him. After all, it was a pretty name.
Persephone grew up in the Crystal Empire, where she got all the love and care a child could ever ask for. As she got older, her coat color lightened (seemingly more every year). Without much known about changelings beside the horrors of an attacking hive, there wasn't a known explanation for her changing color. With Sunburst as her Royal Crystaller, there were plenty of attempts to learn more about her species whenever he wasn't helping her control her magic. As a child, Persie suffered from every known pegasi and unicorn toddler problem there was: growing pains, excessive down feather fall-out, bursts of uncontrollable magic, and spurts of flight ability. On top of that, Persephone was a very finicky foal, crying over every small inconvenience. And as a growing Royal Changeling (even a changeling/unicorn hybrid), she was filled with potent power which was linked heavily to her emotions. Persie can still have rough days with her magic, as it is linked strongly to her state of mind and emotions.
Y'all can basically retcon this, at least when it comes to Sugarverse:
I am absolutely IN LOVE with changeling Flurry, it might be one of my favorite headcanons so far!