I wrote a story with the Guardians of Kandrakar and the female Miraculous heroes competing on Total Drama called Magical Girl Island(and I really hope others write their own), so here's a short story on how their identities were revealed. This is an AU for both universes, so Dark Mother was easier to defeat but she wanted to expose the Guardians to the people of Heatherfield, Chloe isn't such a bully, the other heroes were given their Miraculouses in the beginning and were allowed to keep them, Hawk Moth was defeated already, and Nadja Chamack is unethical and determined to find the heroes' identities. In both universes, how much time passes isn't very clear, so I am being a little vague on how much time is between this and Magical Girl Island. I don't think anyone in Paris knows about the Miraculouses, but I'm sure they would notice that Queen Bee always has a hair comb and Rena Rouge always has a necklace, for example.

Several Months Ago

It was all over the news; five girls in bright blue and purple outfits with wings and magical powers were seen fighting a giant plant-woman in Heatherfield, New York, while the identities of Paris's superheroes were revealed.

The teens were of course trying to hide their identities, but something prevented that from happening. For the girls in Heatherfield, also known as the Guardians of Kandrakar, they did look older, but they didn't look that different from their regulat selves. They also never would have fought an enemy in broad daylight in front of everyone, but in the middle of an underground battle, Dark Mother(the plant-woman), brought them above the ground and hit them so hard that they transformed back into their regular selves. There was still Dark Mother to deal with, so they had no choice but to transform and fight her, and some daring people videoed that and put it online, which showed everyone their secret.

For the Parisian superheroes, their costumes came with masks and their hair changed in color and/or style. There was also magic that prevented people from putting two and two together, but that didn't stop someone with enough determination, and one very determined Nadja Chamack looked for clues, and noticed some similarities between Ladybug and her daughter's babysitter, Marinette. She also noticed that the mayor's daughter started wearing a bee shaped hair comb. Sure, it wasn't colored so she wasn't sure if it was bee shaped, but how many insect shaped hair combs did you see? Never mind that, when she looked closely, she saw some similarities between Queen Bee and Chloe Bourgeois. Upon further investigation, she also saw similarities between some other classmates of Marinette and the other superheroes. Just to be sure, she paid someone to hack into the school and street cameras and looked at hours of video tape footage until she saw Marinette and the others transform, then she showed the videos on her next broadcast.

The videos quickly spread around the world and led to people debating who were better and more powerful. But besides the fan clubs, there were some people, specifically some government agents, who wanted to use them for their own purposes.

Up in Kandrakar, Oracle Yan Lin was about to do something. Technically she couldn't interfere, but now wasn't the time to think about rules. Before she could do anything, there was a flash of light and another her appeared. She explained that she was from an alternate universe, the main universe in fact, and all of this was part of an elaborate plan to destroy the main universe Kandrakar, and that any attempts to erase peoples' memories would just be undone.

After some strategizing, it was determined that eventually, AU Yan Lin would bring everyone to Kandrakar and explain the situation, but first she would make sure everyone accepted and didn't want to hurt them, and would monitor the situation and report to MU Yan Lin.

And so, soon they were so accepted and famous that Total Drama asked them to be on the show. They accepted, and got their own season called Magical Girl Island. Yan Lin decided to let them have their fun on the show before bringing them to Kandrakar. Besides, she wanted to see what the challenges would be and who would win. She also deserved some TV time after watching over all of the worlds and dealing with the Congregation whining about how she wasn't following tradition, dammit!

I hope this story wasn't too short, and I'm planning on having them meet their counterparts in my next Rise of MAGIC chapter, which will hopefully be out this or next week. In this AU, Yan Lin, who held the Oracle responsible for Cassidy's death and was furious at how he treated the Guardians and expected them to clean up his messes, accepted the butterfly in arc 4 and was made the Oracle afer getting Phobos exposed and returned to his body. In a what if issue, we see Irma transform into her regular self after being shot, so it seems that enough pain or damage makes them transform back. Alya, who was determined to discover their secret identities, noticed similarities between Adrien and Cat Noir, so presumably anyone with enough determination will realize the similarities and figure out their identities.