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.
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.
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.
The baby could bring them closer. They'd have a new shared responsibility, which would strengthen their bond. They'd be more focused on each other and the family they're creating.
Well, it could start with Mikasa and Eren finding out they're going to have a baby during a time of rebuilding in their world. The story could focus on how they prepare for the baby's arrival. For example, Mikasa knits baby clothes while Eren tries to build a crib. Their friends also get involved, like Armin giving them advice on parenting based on his knowledge. And the baby might grow up with a special connection to the history of the Walls.
A theme that often comes up is destiny. Fans like to write about how even as a baby, Eren is already on a path towards his future as a Titan - shifter and a hero. It's about how his early days might be subtly guiding him towards that fate. For example, he might show signs of great strength or determination even as a tiny baby. And also, protection is a theme. His family and those around him are trying to protect him from the harsh reality of the world outside the walls, which is a big part of many baby Eren fanfictions.
One possible plot could be that Eren and Mikasa face many challenges while raising their baby. Maybe they have to deal with threats from outside forces who want to harm their family. They might also struggle with adjusting to their new roles as parents.