The jealousy can make them more aware of their feelings for each other. When Levi gets jealous, he might start to realize how much Petra means to him. And the same for Petra. It forces them to confront their emotions instead of ignoring them.
One common theme is the unspoken feelings between Petra and Levi. The jealousy often stems from other characters getting too close to either Petra or Levi. For example, if a new recruit shows interest in Levi, Petra might feel jealous and vice versa. Another theme could be the internal struggle of the characters dealing with their jealousy in a military setting where emotions are often suppressed.
Well, in levi and petra fanfiction, a prevalent theme is duty. They have a sense of duty towards their mission and their superiors, and this often clashes with their personal feelings. Another is the theme of regret. Maybe Levi regrets not seeing Petra's feelings sooner, or Petra regrets not being more forward. The theme of courage is also there. They show courage in battle, but also in their personal relationships, like having the courage to admit their feelings. These themes help to make the fanfictions more complex and interesting.
One possible plot could be them building a life together after the chaos of the Survey Corps. They might face challenges like adjusting to civilian life, dealing with Levi's past traumas that still haunt him. Maybe they start a small family and have to protect their new life from any remaining threats from the Titans.
One great Levi and Petra fanfiction is 'A Soldier's Promise'. It beautifully portrays their relationship within the military setting. Another is 'Petra's Hope', which delves deep into Petra's feelings for Levi. There's also 'Levi and Petra: Unspoken Bonds' that shows their unspoken connection in a very touching way.
It could develop with a lot of mutual understanding. Levi, being the strong but reserved type, would gradually open up more to Petra. And Petra would be there to support him through his nightmares. Their relationship might also grow as they learn to work together in new ways, like running a small business in their post - Survey Corps life.
I really liked 'Sasha and Levi's Unlikely Friendship'. In this fanfic, it starts with a simple encounter between them that gradually blossoms into a strong bond. The author does a wonderful job of writing their dialogues, making it feel very in - character. For example, Sasha's food - loving antics and Levi's exasperated but endearing responses are spot - on.
A good Levi x Sasha fanfic should have well - developed characters. It needs to stay true to their personalities from the original 'Attack on Titan' series. For instance, Levi's cleanliness obsession and Sasha's love for food should be incorporated in an interesting way.
Some great Levi x Reader fanfics in the Attack on Titan universe often focus on their relationship development. For example, 'The Captain's Trust' which shows how the reader character gradually earns Levi's trust during their time in the Survey Corps. Another one is 'A Chance Encounter' that starts with a chance meeting between the two and how their relationship evolves from there.