Fanfiction.net is also a good place. There are a lot of different works related to various fandoms, including Fate series. So, you should be able to find some shirou x saber lily fanfiction by simply searching for the relevant tags.
You can try Archive of Our Own (AO3). It has a large collection of fanfictions, and you are likely to find many shirou x saber lily ones there. Just use the search function.
One great shirou x saber lily fanfiction could be 'A New Beginning'. It explores their relationship in a post - Holy Grail War world where they have to rebuild and find their place together.
For Shirou, his character can be developed by showing his growth in combat skills specific to the Camelot era. He could learn new sword - fighting techniques from Saber Lily. His ideals can also evolve as he experiences the different values in Camelot, becoming more confident in his own beliefs.
One interesting plot could be Saber Lily and Shirou teaming up in the Camelot era to face a powerful, previously unknown threat. Maybe a dark sorcerer who is trying to corrupt the very essence of Camelot. They would have to rely on each other's strengths, with Shirou's determination and Saber Lily's combat skills.
In fanfiction, Shirou and Saber's love is often depicted as a complex and beautiful relationship. It's a love that transcends their different natures. Shirou, with his strong sense of justice, is drawn to Saber's noble and powerful presence. Their love story can be full of moments of understanding and mutual growth.
One common theme is love. Their relationship is often explored in different ways, from a slow - burn romance to an instant connection. Another theme is loyalty. They are both loyal characters, and in fanfiction, this loyalty is often tested and reaffirmed.
There's a fanfiction called 'Married Bliss: Shirou and Saber'. In this story, they get married and start a family. It focuses on how Saber adapts to a more peaceful life, away from the battles she was used to. Shirou is always there to support her, and their love for each other just grows stronger with each passing day.
Growth is also a prevalent theme. Both characters grow as individuals within their marriage. Shirou might become more confident and assertive, while Saber may learn to be more open and emotional. This is often shown through various events in their married life in the fanfiction, like dealing with financial issues or making big decisions together.
One common theme is sacrifice. Shirou is often willing to sacrifice himself for Saber, and vice versa. It shows the depth of their love.
Character development is crucial too. If the fanfiction shows how Saber and Shirou have grown as individuals and as a couple, the kiss becomes more meaningful. It could be that through various trials, they have come to understand and love each other more deeply, and the kiss is a physical manifestation of that.
Well, 'Eternal Bond' is a really nice fanfic on this topic. It starts with their wedding and then goes on to show how they support each other in their respective goals. They have deep conversations and grow even closer as a married couple. There are also some really cute fanarts associated with it that enhance the reading experience.