One idea could be the reader being a new student at the DWMA. They could struggle to find their weapon partner at first, but then end up with an unexpected and powerful weapon. Another plot could involve the reader having a special ability that draws the attention of the Kishin's minions, leading to various battles and the need for protection from the main Soul Eater characters.
Another plot could be that the reader is an outsider to the world of Soul Eater, perhaps from a different dimension. Soul accidentally discovers the reader and at first is suspicious. But as he gets to know the reader, he realizes that they are kind - hearted. They then have to deal with the challenges of the reader adapting to the Soul Eater world while also falling for each other.
One plot idea could be that the reader is a new student at the DWMA and Stein takes them under his wing as an apprentice. As they work together, they start to develop feelings for each other. Another could be that the reader has a special power that Stein is intrigued by and he tries to study it, which leads to them getting closer.
One idea could be a story where the main character discovers a hidden power within their soul that has the potential to either save or destroy the world in the Soul Eater universe. They then have to struggle with the moral implications of using this power.
Maybe an OC that has a special ability related to time. They can slow down time briefly during a fight. But this power comes with a cost, like it drains their soul energy quickly. The fanfiction could explore how they learn to control this power and balance its use while also dealing with the normal challenges at the DWMA, such as making friends and passing classes.
One idea could be a reader who suddenly finds themselves in the Pokemon world during a big Pokemon tournament. They have to quickly learn about the different Pokemon types and battle strategies to compete. Another plot could involve the reader being a Pokemon trainer from a different dimension where Pokemon have unique abilities not seen in the normal Pokemon world. They then have to adapt and use these new abilities to their advantage while making friends and facing rivals.
A third plot idea could be the reader being a time - traveler from the future. They come to the present in the Soul Eater world to prevent a great disaster that will happen if certain events aren't changed. The reader teams up with the main characters, using their knowledge of the future to help them in battles and make strategic decisions. This would involve a lot of adventure, mystery, and the building of relationships between the reader and the Soul Eater characters in a non - inappropriate way.
Another type of Soul Eater reader fanfiction involves the reader being from a different dimension. They get pulled into the Soul Eater world and have to adapt. This can lead to really cool crossovers in the story, like bringing in elements from the reader's home dimension and seeing how they clash or blend with the Soul Eater universe.
One idea could be a crossover where the Juubi's power somehow gets transferred to a character in Soul Eater and they have to learn to control it. Another could be Naruto getting lost in the Soul Eater world and having to adapt to their way of fighting and dealing with souls.
Well, you could have a witch OC fanfiction where the witch is an outcast among her own kind. She doesn't believe in the typical evil ways of witches and wants to use her powers for good. So she approaches the DWMA with an offer of peace and cooperation. Another plot could be that the witch OC has a hidden lair where she collects ancient artifacts that have the power to change the balance between witches and the DWMA. And a third plot idea is that the witch OC is in love with a DWMA student, and this forbidden love creates a whole lot of drama and challenges as they try to be together in a world where witches and DWMA are usually at odds.
One idea could be that Naruto characters are transported to the Soul Eater world. Naruto's determination could be a great asset in the battle against Kishin Eggs. He might use his shadow clones to surround and overpower the enemies. Another plot could involve the weapons from Soul Eater trying to learn Naruto's ninjutsu. For example, Soul could be interested in the Rasengan and try to incorporate it into his fighting style. Also, Maka's strong sense of justice would blend well with the Naruto characters' values, and they could team up to take on powerful foes together.