Ladybug x Conner Young justice
( ladybug and chat noir are way more powerful than in the cartoon as the miraculous are way more powerful but the ladybug and cat are still the most powerful) ( the miraculous gives the holder all the fighting skills of previous holders, so ladybug and cat noir know thousands of years old martial arts)
Marinette Is the Biological Mother of conner ( from young justice) Lex couldn't use his DNA with Superman.
So he searched the whole world for the best match, and he comes across secret videos of Paris's and their superheroes ladybug, and chat noir.
The parish government had a meeting with ladybug who suggested that they wouldn't contact the justice league and that no footage of akumas should go outside Paris.
As if superman got akumatised it would be a problem. It might take a while but they would be able to defeat him.
He hires a person to steal DNA from ladybug (he doesn't know their secret identity's as the magic protects them)
Years later ladybug has defeated hawkmoth and cat noir who betrayed her, cat noir had also gone crazy saying they were soulmates either though Marinette always thought of him as a brother. she also thought of Adrien as a brother as she pretended to have a crush on him.
Marinette is actually Aromantic, she only acted like she had crushes, and she didn't stalk Adrien she has every one of her friend's schedules so she knows where they are at an Akuma attack.
Marinette is still ladybug but she also uses the other miraculous. She doesn't have the kwamis stuck in the box like the previous guardian she treats them like her siblings/best friends.
Marinette is the grand guardian whose soul is a perfect match for every miraculous.
When the group lets conner out of the tank Marinette feels a magic signature that seems to be an almost exact copy of her magic from halfway across the world.
it takes her a while to figure out why a copy of her magic signature is halfway across the world. The kwamis help and they figure out someone has taken her DNA.
She starts tracking it and it takes her months as it kept on disappearing and moving. ( the cave has magic wards that block magic signatures)
When Connor finds out lex tried to use his DNA to make him but ended up having to use a woman's DNA he starts trying to find the name of the woman's DNA. But he never finds her name. He wonders if his mum knew what lex was doing or if maybe lex killed her to take her DNA