Chloe becomes a magical girl AU
Post season 3, days after Miracle Queen, André decides that it would be best if Chloe takes a break from Paris and its akumas and goes somewhere with less danger, at least for a while (plus, while everyone believes that she was an unwilling victim of akumatization, she was still the cause of the identity reveal of the temporary heroes, which people are still angry about). So he gets her a vacation to another country that will last a month or two or three. She'll have to take online classes to keep up with her schooling, but outside of that, she'll be able to relax and destress.
So now Chloe is in a new place (I don't know where a good vacation destination would be). But she's still a bit messed up about the whole Miracle Queen incident; she's angry, hurt, guilty, desperate, and overall full of despair. So obviously, Kyubey approaches her with an offer. He tells her that he will grant any wish she desires if she makes a contract with him and becomes a magical girl.
And Chloe, desperate, alone, full of emotion, and vulnerable, agrees and wishes to become a hero again.
The reason why Chloe is inclined to trust Kyubey is a combination of her experience with the kwamis, her susceptibility to manipulation, and most importantly, that Kyubey sounds exactly like someone Chloe trusts and cares about. His voice is so familiar; it's like she's hearing the voice of her friend instead of an alien cat thing (this is purely because Sabrina and Kyubey have the same voice actor in the English dubs of their respective shows and also chlobrina angst), so Chloe is less guarded and more willing to trust Kyubey.
(Also, Kyubey is very persistent, even more so with Chloe, since she was a former miraculous holder, which means she has a lot of karmic destiny or whatever. Kyubey usually doesn't go after miraculous holders because the kwami with said holder are always hostile, and he is not messing with that. But now he can go after a former miraculous holder since Chloe doesn’t have a kwami to warn and protect her.)
Chloe goes on her first fight against a witch or wraith or something, and she's doing pretty well. She continues this for a week or two before meeting a veteran magical girl who offers to teach her. Chloe refuses; a fight ensues, and Chloe, despite putting up a decent fight, ultimately loses due to a lack of experience. She reluctantly agrees to become the magical girl's mentee, and things are going pretty well for her. She even has someone to help her with her issues, maybe even give her some friends, a rival even.
(It would be interesting if the mentor knew what soul gems are but not how witches are made if this is set in the timeline where witches are a thing.)
I wonder if it would be sadder if either Chloe's mentor or rival dies protecting her or if they just fall into despair. Like, of course, having someone you care about die while saving you would mess you up. Wouldn't it be interesting if whoever dies does so by becoming a witch/getting taken by the law of cycles? With the law of cycles, it would probably give her a crisis and all that and maybe it can give her a chance for closure , but if her mentor/rival turns into a witch and she has to be the one to kill it because if she doesn't, it'll kill someone else, then all of that. But she doesn’t want to kill someone she cares about; there is still a part of her that clings to the hope that she can save them, but in the end she is forced kill the witch for the greater good.
So in the middle of all of this, Chloe has to go back to Paris, and she tries convincing her dad to let her stay a bit longer, but he (surprisingly) isn't budging. So Chloe is forced back to Paris, and she is not doing great.Meanwhile, everyone else is weirded out by how weird Chloe is acting; she isn't her usual mean and antagonistic self, but the strangest thing is how tense and guarded she gets when Sabrina talks.
Also, Lila being Paris's resident magical girl (or at least having significant territory) sets up a slow burn friendship between Chloe and Lila.
Lila resents the miraculous holders because, to her, they get all the pros of being a magical girl (powers, saving people) and none of the cons (having your soul ripped out of your body, the fact that "you either die a hero or end up becoming the villain" literally applies to you, low life expectancy, and if you know about how witches are made, grappling with murdering other magical girls and how you must continue to do so to survive). They even have kwamis and no Kyubey. Also, they get fame and acknowledgment for their work, and Ladybug can fix anything. So, Lila is very pissed that they're living the life she wanted.
