Ugh! I had this idea to write a fic about what-if Marinette was evil instead of Gabriel! But now with the whole Shadybug and Claw Noir special coming, I feel I have to wait, so things like 'Good Gabriel's good guy name' and what he calls who makes heroes (currently I'm calling them champion but I don't know anything) are more accurate to the show!
Essentially, it would've been in this universe, so no Shadybug. Instead, her name would've been Miss Fortune (I've been in this fandom since the beginning, I've always wanted that name to be canon). She takes the image of a shy sweet girl Marinette Dupain-Cheng but when things don't go her way, she becomes Miss Fortune.
Luckily, Paris has a hero in its corner, the amazing Chat Noir who battles the evil Miss Fortune. However, he also has an ally in the form of Papillon, a mysterious benefactor who helps him by sending him champions.
Adrien will still be our innocent sunshine child, but he has a whole lot more on his shoulders, trying to stop Miss Fortune from wrecking havoc and eventually becoming Guardian.
As Chat Noir, he and the champion have to work together to fight Miss Fortune. I have this system where Miss Fortune has a anti-charm (like Anti-bug) and if the two destroy it, the world healing begins.
Alya is still how she is in the show. Except she despises Miss Fortune. Her blog is towards Chat instead and she insults Miss Fortune anyway she can. She wants to rid the world of Miss Fortune, unaware she's her best friend.
Chloe would be a much better person (she still has some of her original flaws, so she would be not be like Zoe), liking Adrien like a brother and treating Sabrina like a real friend. Of course, Marinette doesn't see their relationship as platonic so she targets her. This version of Anti-Bug would've have Papillon give Chloe the power of the original Ladybug miraculous until Chat decides to give her the bee miraculous to use.
Lila would've been a person who always told the truth and while not all of her stories from canon were true, she does have some real amazing tales. This attracts Adrien to her (again platonically) much to Marinette's chagrin. One story is that Miss Fortune stole her bag once and Chat Noir got it back for her. Marinette thinks Lila is lying and Chat doesn't remember Lila specifically but he does remember giving someone back their bag.
So she briefly becomes Miss Fortune to embarrass her but this just inspires her to become Volpina and her and Chat briefly work together to take her down.
Gabriel is a much better father here! He's still busy and Emilie is still dead. But he's allowed Adrien to go to school and have a less stricter lifestyle. He still misses his wife but goes on a more healthier path instead and tries to move on while helping Chat Noir as Papillon.
Zoe would've been a person who acted nice when in reality, she's a massive witch. She still has feelings for Marinette but Marinette takes advantage of these feeling instead. She assist Miss Fortune also, not liking when things don't go her way. Half of Chloe becoming akumatized episodes would be Chloe either needing the bee miraculous or her helping Chat as a champion. Zoe would play dumb when confronted but some people start seeing the truth through her and Marinette's lies.
So Marinette likes Adrien to disturbing degrees. Finding her strange since kindergarten, Adrien at best can be civil towards her. In the Animan episode of this AU, he would've weirded out by Nino's crush on her but would've still helped him, because he's a good friend and he feels he would be a good influence of her.
He and Miss Fortune jokingly flirt with each other sometimes, but they really hate each other with a fiery passion.
Adrien is bisexual in this fic. Who is Adrien's partner? Luka. Instead of liking Marinette, he takes a shining to Adrien instead. Adrien is smitten as both himself and Chat Noir. Luka would be a frequent character in season 1. Often times, Chloe and Juleka (and sometimes Nino) would try pairing them together frequently.
Marinette used to have a crush to Luka and he used to give her a chance but with all the lying and her accidently making it clear she likes Adrien, he also can now only be civil to her.
Chloe is also bisexual. Nathaniel initially has feelings for her instead of Marinette in 'Evilluastor'. Season 1 would plenty of cute moments. Not sure I should write whether they broke up but are on good terms or have them be in a poly relationship with Marc and Kagami.
Down the line, Chloe gains feelings for Kagami. Marinette in this AU, never lets go of her mean feelings for Kagami and instead Kagami enters the scavenger hunt in 'Ikati Gozen' with Chloe, causing the two to bond. Kagami never has feelings for Adrien (but I'll say it again, Marinette doesn't see it that way).
That all I have to write, bye!