Jaune could be a character created specifically for this fanfiction. Maybe he's a hero - in - the - making who is just starting to discover his abilities but is held back by his fear of funus.
In Marinette x Lila fanfics, a frequent theme is the exploration of their complex relationship. Since they are often at odds in the original show, fanfics might focus on how they overcome their differences. There's also the theme of hidden feelings. Maybe Marinette has some unacknowledged feelings for Lila beneath her initial dislike, or vice versa. And sometimes, there's the theme of a shared adventure that brings them closer together, like facing a common enemy in the Miraculous Ladybug universe.
It could be the protagonist. The one who has always been suspicious of Lila's stories and has been quietly investigating. They might finally gather enough evidence and expose her.
There are likely some out there. You can start by checking popular fanfic websites like Archive of Our Own. Just search for 'female Jaune Arc x male' in the search bar, and you might find some interesting stories.
It could be that Jaune has some sort of traumatic past experience with funus, which makes him scared. Maybe he witnessed its destructive power or had a personal encounter that left him with deep - seated fear.
Jaune is the character who has been expelled, so he is central to the plot. His character might be dealing with feelings of betrayal, confusion, and a desire to clear his name. The OC, on the other hand, could be a very unique individual. They might have their own goals and motives that initially seem separate from Jaune's situation. But as the story progresses, their paths become intertwined. For example, the OC could be a healer who decides to help Jaune because they sense his innocence, and their relationship develops from there.
You can start by looking on fanfiction platforms like Archive of Our Own (AO3) or FanFiction.net. There are often tags and search filters that can help you narrow down to Marinette x Lila fanfics. Some authors might also post their works on Tumblr or Wattpad, so it's worth checking those places as well.
One reason could be the novelty of the pairing. It offers a different take on the relationships within the story's universe. People are often drawn to unique pairings.
Rather than engaging with potentially inappropriate fanfiction, it's better to look for fanfiction that promotes positive values, such as friendship, teamwork, and character growth in the context of the Jaune and Ruby relationship.