The idea of Eren Yeager in a harem scenario is interesting because it takes a character from a serious and often dark story and puts him in a more light - hearted, relationship - focused situation. It allows for different character interactions that we don't see in the original work.
There are various 'Eren Yeager x Harem' fanfictions. Some stories could be about Eren being in a harem situation where he has to balance his duties and his relationships. Maybe in one, he is training to fight Titans while also navigating his feelings for multiple girls. These fanfictions often play with the existing character dynamics and create new scenarios for the characters to interact in.
A great Eren Yeager OC fanfiction I read was about an OC who was a half - Titan. This OC had to hide their true nature from everyone, including Eren at first. But as the story progresses, they reveal their identity to Eren and together they try to find a way to end the Titan curse once and for all. It's full of action, drama, and explores the complex relationship between humans and Titans in a new way.
First, think about your OC's personality. Are they brave like Eren or more cautious? Then, decide on their backstory. Maybe they come from a family of outcasts within the walls. Next, consider how they will interact with Eren. Will they be friends, rivals, or something else? After that, plan out the plot. It could be about a new threat to the walls that only your OC and Eren can face together. And don't forget to give your OC unique abilities or traits that will make them stand out in the story.
A prevalent theme is protection. Eren is usually depicted as the protector of his harem, and in return, they offer him emotional support. Also, the theme of growth is common. As the story progresses, both Eren and the members of his harem grow as characters. They learn from their experiences together, and their relationships also evolve. For instance, they might start off as just friends or comrades and then develop deeper romantic feelings. There's also the theme of sacrifice, where sometimes a member of the harem might be willing to sacrifice themselves for Eren's sake or for the sake of the group.
One popular 'Attack on Titan Eren x Harem' fanfiction is 'Eren's Unconventional Bonds'. It delves into interesting relationships between Eren and multiple characters in a unique way. Another one could be 'Eren's Harem Adventures' which has some exciting plot twists involving Eren and his harem members. There are also many on fanfiction.net, you can search there using relevant tags to find more.
A simple fanfiction could be that Cade Yeager discovers a hidden ability within Optimus Prime that no one else knew about. This ability helps them defeat a powerful enemy that was about to destroy the Autobot base on Earth.
Female Eren in this fanfiction is often portrayed as headstrong. Just like her male counterpart, she has a strong sense of justice and is determined to fight for what she believes in. She is also likely to be brave, not afraid to face danger head - on, whether it's in battle or when confronting the complex relationship with Levi.
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.