It's hard to say. 'Levi x Eren' fanfics are quite common in certain fandoms, but the 'Levi is a criminal' aspect makes it a more specific and perhaps niche sub - genre. If there are a lot of fans who like to see dark or morally ambiguous takes on the characters, it could potentially be popular within that subset of the fandom. However, it also might not be mainstream popular as it goes against the more typical heroic portrayals of the characters.
One idea could be a story where Levi and Eren are on a dangerous mission together. They start off not getting along well due to their different personalities. Levi is strict and methodical while Eren is impulsive. But as the mission progresses, they gradually learn to understand and rely on each other. For example, Eren might save Levi from a Titan in a moment of quick thinking, and Levi in turn teaches Eren some crucial combat skills.
Maybe Levi is a criminal in the sense that he's part of an underground rebellion against an unjust regime. Eren, who is initially on the side of the establishment, meets Levi and gradually comes to understand his motives. Their relationship could develop as Eren has to decide whether to side with Levi or stay loyal to the regime, all while a romantic connection forms between them.
One aspect of Levi x Eren family fanfiction could be the exploration of their relationship in a family - like dynamic. It might involve how they support and protect each other within this new family structure. For example, Levi could be a strict but caring figure, while Eren is the one with new - found responsibilities in this family.
To develop their relationship realistically, let them communicate. Have them have conversations about their pasts, their goals. Eren might talk about his family and his drive to avenge them, and Levi could share some of his own traumas from his past. This would create a deeper understanding between them. Also, small acts of kindness like Levi patching up Eren's wounds after a fight or Eren getting Levi his favorite tea could strengthen their bond.
There's also 'Eren's New Perspective'. In this fanfic, female Eren brings a fresh view to her relationship with Levi. It delves into how their different personalities clash and mesh. The story often has them facing challenges together and growing closer through shared experiences.
There's also 'Levi's Treasure'. It's a fanfic where Levi's possessiveness towards Eren is more of an emotional kind. The story delves deep into their characters, exploring how Levi's past experiences shape his possessive attitude towards Eren. It has some really heart - touching moments that make it a great read for fans of this pairing.
Levi's overprotection can also shape the relationships in the plot. Other characters might view Levi's actions towards Eren in different ways. Some might support Levi, thinking Eren needs that protection, while others might side with Eren and encourage him to be more independent. This can lead to various sub - plots and further development of the overall story.
Fanfiction about Eren and Levi kissing can be quite interesting. It might explore a different side of their relationship. Some fanfictions in this regard could be about a moment of emotional intensity between them, where the kiss represents a deep connection that goes beyond their usual interactions in the original story.
A good 'female eren x levi fanfic' often has well - developed characters. The author should stay true to the core personalities of Eren and Levi while also adding new dimensions due to Eren being female. For example, female Eren might have different emotional responses or ways of interacting.