Well, it could be that Nero accidentally breaks some important rule in his world. Maybe he accidentally damages a powerful relic that is crucial for his community's safety, and then he has to face the wrath of the elders or those in charge.
Well, in addition to Mana and Mahad, there could be other supporting characters. For instance, there might be an elder or a teacher figure who is aware of Mana's actions and Mahad's attempts to deal with her trouble. Or perhaps there are other young magic users like Mana who are affected by her getting in trouble, either by getting involved in her mess or by learning from her mistakes.
A power - hungry politician in Nero's world could be the main antagonist. They see Nero as a threat to their power or as an easy target to gain more influence. They manipulate situations to make it seem like Nero has done something wrong.
It could be that she challenged the teacher's theory too forcefully. Hermione is known for her intelligence and eagerness to prove her point, which might not always sit well with some teachers. For example, if the teacher was presenting a more traditional view on a magical concept and Hermione had new, radical ideas based on her extensive reading, the teacher might take it as disrespect.
Maybe Mana gets in trouble when she ventures into a forbidden area in the fanfiction. Mahad then has to decide whether to help her or follow the rules. It could be a story of loyalty and the struggle between following the law and helping a friend. For example, if the forbidden area is full of dangerous magic, Mahad might risk his own position to save Mana from the perils there.
She might lose her friends. In fanfiction, when a character like Angelica gets in trouble, it often leads to a strain in relationships. Her friends could start to avoid her, thinking she's a bad influence or too much trouble to be around.
It could be that Bella gets in trouble with Carlisle because she disobeyed one of his rules. For instance, if she went out alone at night in a dangerous area where there are other vampires who might not be as friendly as the Cullens. Carlisle, being the patriarch of the family, would be concerned about her safety and the safety of the family as a whole. So, he might restrict her activities or give her a stern talking - to.
Another consequence could be the loss of friendships. If she flirts with her friends' partners, it can create a rift not only in her own relationship but also in the friendships. Her friends may feel disrespected and cut ties with her. This can leave her feeling isolated and lonely. In some cases, if the flirting gets really out of hand, it could even lead to legal issues, like if it is considered harassment.
She might face consequences from the other characters. For example, if she's in a school - based fanfiction, she could get detention. The authority figures in the story, like teachers or elders, would likely discipline her for her bad - ass behavior that led to trouble.