There could be more serious consequences too. Maybe she is even punished by some authority figure in the fanfiction. For example, she could be banned from certain places or activities, all because she was wrongly framed for hurting Lisanna. This would not only affect her socially but also limit her opportunities within the story's setting.
Lucy could face isolation. People in the fanfiction world might avoid her, and she could be left all alone. This could also lead to her losing confidence in herself as she is constantly being blamed for something she didn't do.
In the fanfiction world, it might be part of a bigger plot against Lucy. There could be a character who is jealous of Lucy's relationship with other characters. So, they decide to frame her for hurting Lisanna as a way to get her in trouble and drive a wedge between her and her friends.
The plot could involve jealousy. Lucy might become jealous of Lisanna as she takes over her position in the guild. This could drive Lucy to train harder and become more independent. Maybe she'll find a new group of friends or allies who see her value outside of the guild.
In a fanfiction of Lucy being replaced by Lisanna, it might explore the emotional turmoil of Lucy. She could be heartbroken seeing how easily she was seemingly replaced. Meanwhile, Lisanna might not be fully aware of the situation or might be caught up in the sudden popularity. This could create a rift not only between Lucy and Lisanna but also within the guild as a whole. Some members might side with Lucy, feeling that she was unjustly pushed aside, while others might be excited about Lisanna's presence and not understand Lucy's pain.
Lisanna might face a lot of backlash from the guild. Her friends could be disappointed in her and might not trust her as much. She could lose her standing in the guild and have to work hard to regain people's respect.
Perhaps Natsu is under the influence of a powerful and dark magic that makes him lose control of himself and accidentally hurt Lucy. It could also be that Natsu is trying to protect Lucy from something but his actions end up causing her harm instead. Like if he tries to keep her away from a dangerous situation by pushing her too hard and she gets injured.
I'm not sure specifically as there could be many interpretations. It might be about a character named Lucy obtaining all 12 keys in a fictional world. Maybe these keys are magical or important items that are crucial for a certain quest or storyline within the fanfiction.
Maybe it could be about how her friends take care of her. They might bring her medicine, make her soup, and stay by her side to comfort her while she's dealing with the fever.
One potential consequence is getting a negative reputation within the fanfiction community. Readers may avoid the author's other works. Also, it could be flagged as inappropriate content on many platforms.
The power balance in the fanfiction world could be different. Without Lucy, Fairy Tail might lack some of the strategic and magical capabilities she would have brought. At the same time, Lucy could be a major force in another part of the fictional world, changing the political and magical landscape there. It also means that the relationships and story arcs that typically involve Lucy in the original Fairy Tail story will be completely different, creating a whole new set of stories and interactions.
One consequence could be that her real relationships get strained. If she already has friends or a potential love interest in the fanfiction world, drinking the love potion might make her act out of character towards them. She could neglect her true friends or push away someone who actually cares for her because she's under the influence of the love potion's false feelings.