Well, it depends on the popularity of the characters Katie and Shiro within their respective fandoms. If they are from a well - known series, there may be a good amount of fanfiction about them getting married. However, if they are more niche, it might be a bit harder to find. You could also try reaching out to fan communities dedicated to the works they are from to see if anyone knows of such fanfictions.
It could be about their new life together after getting married. Maybe how they adjust to living in the same house, sharing daily routines, and dealing with in - laws if that's relevant in the story's universe.
Love and commitment are common themes. Since they are getting married, the fanfics often explore how deep their love is and their commitment to each other through different situations.
One great fanfiction could be 'A New Beginning' where it details their journey from friends to lovers and finally getting married. It beautifully portrays their relationship growth.
One possible story could be that Shiro, as a powerful female, becomes an equal to Gilgamesh. She might use her unique powers to challenge his authority in the fanfiction world. Maybe she has some sort of magic or combat skills that make her stand out. She could start as an unknown figure but gradually gain recognition and respect from Gilgamesh and other characters in the story.
I'm not very familiar with this specific 'ganta and shiro lemon fanfiction'. However, generally in fanfiction, it might explore the relationship between Ganta and Shiro in unique ways. It could involve their adventures together, how they support each other, or the development of their feelings for one another. But without reading it specifically, it's hard to give a more detailed analysis.
There are many places to find Shiro and Keith yaoi fanfiction. Fanfiction.net and Archive of Our Own (AO3) are two popular platforms. On these sites, you can search for tags related to Shiro, Keith, and yaoi to narrow down your results. Just be aware that the quality of the fanfictions can vary widely.
For Katie, she could be developed by giving her more complex emotions. For example, instead of just being a meek character, she could have moments of great strength and determination. Maybe she has a secret dream that she's been too afraid to pursue until she meets Luke. Luke, on the other hand, could be developed by showing his insecurities. Despite his seemingly confident exterior, he could be afraid of not living up to his family's expectations. Their relationship could then be a journey of them helping each other overcome their respective fears.
For Katie, I could see Zendaya. She has the ability to portray a strong - willed yet vulnerable character, which would be perfect for Katie. As for Luke, Timothée Chalamet would be a great choice. He has that boyish charm and can bring out the kind - hearted and somewhat naive side of Luke that would be expected in a Cinderella - inspired story.