Daminette but with immortal time travel shenanigans
So, this idea sprang to mind after rewatching the Pharaoh episode and now won't leave me alone.
(This kinda sorta follows the ML Universe timeline, but it very much does not follow DC timeline because what even is that)
Marinette isn't 3000 years old, of course not, that would be silly. Afterall, she has the parents to prove it. Tikki even admitted that there were past holders. But what if that wasn't quite the case?
One day, Marinette is just minding her own business when she's sucked back in time to ancient China. She wakes up on the floor of a workshop, surrounded by a cast of characters in various clothing styles (you can go with either new characters or established characters, but Damian in his Robin era is one of the characters (Bonus points if young Alfred is there too)).
The crafter of the miraculous had messed up when making the Bunny miraculous and accidentally summoned holders across time. He does not know how to fix it yet, but he will. Until then, everyone gets the miraculous which they were most acquainted with. (Damian is obviously the black cat).
(Cue saving people and relationship dynamics being formed with everyone)
Then the mage fixed what happened and had to send everyone back to the future. But it doesn't quite work as expected. Marinette wakes up on the floor of a temple surrounded by her friends and suspicious Guardians. Apparently, they were only sent forward a little bit in time.
Marinette becomes Piáo Chóng, the ancient Chinese Ladybug, and Damian, Hēi Māo (go look at his picture because he looks a lot like Damian).
(Cue historic montage of Marinette being basically every ladybug with her group of friends and falling in love with Damian.)
But then Marinette wakes up, not surrounded by her friends, but back in her old home. No time has passed for others, but she's lived lifetimes. (It might be funnier to go the Lila & Co. salt route, because after living for centuries, Marinette would definitely have forgotten a lot about the life she used to live).
Her ladybug suit changes and she acts a lot differently now, leading people to believe she's a completely new ladybug. She plays up the thousands-of-years-old thing (not like it's hard) and convinces people the old ladybug was just a placeholder until she came back. (Chat obviously does not take this well, and how not well is up to you).
Anyways, stuff happens, maybe Hawkmoth is defeated. She reunites with some of her time-traveling buddies. Then Ladybug meets the Justice League and Damian as Robin is there. But he hasn't time-traveled yet, so he's not her Damian.
Ladybug is angsty. Robin is confused. Batman is suspicious. And everyone else does not mind their own business.
One day, Ladybug is watching Robin from afar, and a time-traveling buddy starts talking about unhealthy coping habits. Ladybug rants, and Robin overhears. Cue suspicious Batfam.
Then Damian time-travels.
Edit: Oh my goodness, someone wrote my idea! Go check out Leia's awesome work on AO3!!
