Well, in this fanfiction plot, perhaps they get married as a strategic move at first. Lelouch thinks it will strengthen his position among the resistance forces with Kallen by his side as his wife. But as time goes on, they start to develop real feelings for each other. Kallen, who was initially skeptical, begins to see Lelouch in a new light and they build a relationship based on mutual understanding and respect. The story could then focus on how they navigate their new married life while still dealing with the political and military challenges around them.
One possible fanfiction could be a post - war scenario. After the chaos and destruction in the Code Geass world, Lelouch and Kallen, having fought side by side, realize their deep connection. They start to rebuild the world together and gradually their friendship turns into love. Eventually, they get married in a small, private ceremony attended by their closest friends and allies. The fanfiction could focus on how they overcome the differences in their backgrounds and the challenges of leading a new world while being in love.
I also like the fanfiction 'Beyond the War: Kallen and Lelouch's Married Life'. It delves into their married life, showing how they support each other in building a new world. It shows their daily interactions, the little arguments and the great love they have for each other.
One possible plot could be that after a dangerous battle where they almost lost each other, the tension and relief lead to a kiss. It could be a moment of realization for both of them about their deeper feelings.
I'm not sure if there is a specific fanfiction about that. Fanfiction can cover a wide variety of scenarios, but this particular one might be quite rare or might not be in the mainstream. You could try searching on popular fanfiction websites like Fanfiction.net or Archive of Our Own.
One possible plot twist could be political interference. Maybe the marriage was initially a political move, but as they spend time together, they truly fall in love. However, their respective kingdoms' political interests start to clash, putting their relationship at risk. For example, there could be factions within each kingdom that oppose the union for various reasons like power struggles or long - standing feuds.
One possible plot development could be that Kallen starts to question her own identity and purpose without Lelouch in a romantic sense. She might then throw herself into her work or other relationships. Meanwhile, Shirley and Lelouch could face challenges in their marriage, like political or social pressures, and Kallen might be reluctantly drawn back into their lives to help them.
One challenge could be political opposition. Since they come from different backgrounds, there may be groups who oppose their union for political reasons. Another is the public perception. They might have to deal with the opinions of the general public, which could be divided.
Another theme is unity. Kallen and Lelouch come from different backgrounds. Their marriage symbolizes the unity of different factions or ideologies. In the fanfictions, this often leads to a more harmonious world where different groups start to cooperate more. For instance, it might show how their union affects the relationship between the Britannians and the Elevens.
One possible plot could be their adjustment to married life while still dealing with the political aftermath in their world. They might face challenges from different factions who are not happy with their union.
A plot could involve Lelouch and Kallen being forced to work with an old enemy in order to stop a greater threat. At first, they are hesitant and distrustful, but as they face difficulties together, they realize that they can use this situation to their advantage. This situation also brings them closer as they share their strategies and secrets.