The plot could revolve around their friendship during a difficult time within the walls. Maybe there's a shortage of resources, and they have to work together to ensure the survival of their group. Christa uses her diplomatic skills, while Ymir uses her combat abilities. Their cooperation not only helps the group but also deepens their connection.
In a fanfic, Christa and Ymir might find a hidden place within the walls. This place has secrets about the origin of the Titans. As they explore it, they learn more about each other. Christa could discover Ymir's past and understand why she is the way she is. Their story could be filled with mystery and adventure, and in the end, they become even closer friends.
Popular themes in Ymir x Christa fanfics include growth. Both characters can grow as individuals through their relationship. Ymir might become more empathetic and Christa more confident. Another theme is the exploration of secrets. Since both characters have their own secrets in the original story, fanfics can delve into how they share or keep those secrets from each other. And finally, the theme of hope. Their relationship can be a symbol of hope in the otherwise dark and violent world of Attack on Titan. For example, they might give each other the strength to keep fighting against the Titans.
One possible fanfiction could be about their adventures together within the walls. Maybe they discover a hidden passage that could potentially change the fate of the Survey Corps. They might face Titans together and in the process, their bond deepens as they rely on each other's skills and instincts.
Ymir's character could be developed by exploring her past more deeply. For example, her time as a Titan before joining the Survey Corps. This could make her more complex as she struggles with her identity. Christa, on the other hand, might develop by breaking out of her 'nice girl' persona. As she faces more challenges with Ymir by her side, she could become stronger and more assertive.
The relationship between Ymir and Christa in Attack on Titan fanfic is often a focal point. Ymir's character is complex and her connection with Christa adds another layer to it. In many fanfics, they start off as comrades but gradually develop a deeper connection. It could be due to their shared experiences in the Survey Corps or the harsh environment they live in. Their relationship might also be influenced by the power dynamics within the story. For instance, Ymir's abilities might play a role in how she protects Christa. And their relationship might not be without conflicts, as they both have their own goals and personalities, which can lead to interesting plot developments in the fanfic.
One interesting plot could be Ymir protecting Christa in a dangerous situation within the walls. Maybe when Titans are attacking, Ymir uses her unique abilities to fend them off and keep Christa safe. Another plot could be a story about their friendship growing deeper as they face the secrets of the world together. They might discover something about the origin of Titans that changes their perspective on everything.
One more concept could be a time - travel fanfiction. Christa and Ymir are sent back in time to a crucial moment in the history of the walls. They then have to use their knowledge of the future to try and change things for the better. Their relationship would play a key role in how they approach this new situation and the decisions they make.
Love and sacrifice is also a significant theme. In some fanfics, their love for each other is so strong that they are willing to sacrifice themselves for the other. This shows the depth of their relationship and how much they value each other in the dangerous world of 'Shingeki no Kyojin'.
A great plot for such a fanfic could be that Mikasa's Titan form is a result of a connection to an ancient Titan power. As she becomes a Titan, she starts to have visions of the past, of how the Titans came to be. She then decides to use this knowledge and her new form to try and end the Titan - human conflict once and for all. Along the way, she has to face her friends who are initially scared of her but eventually come to accept her new form as she proves that she is still the same Mikasa deep down, just in a different body.
One possible plot could be that the ponies accidentally end up in the Attack on Titan world through some sort of magical portal. They then have to figure out how to survive in this harsh environment. They could use their unique pony abilities, like Fluttershy's connection with animals, to try and understand the Titans better. Maybe they could even find a way to communicate with the Titans and find out if there's a way to stop the attacks without all the bloodshed.