Well, there's 'Shirou Emiya: The Mentor'. In this fanfic, Shirou takes on the role of a mentor to a young mage. It shows a different side of him, his wisdom and patience. Also, 'Shirou's Adventure Beyond Fate' is quite good. It sends Shirou on an adventure in a different dimension, facing new challenges and making new allies.
One interesting Shirou Emiya fanfic could be 'A Different Path for Shirou'. It explores what would happen if Shirou made different choices early on in the story. Another is 'Shirou's Hidden Powers', which delves into undiscovered abilities of Shirou Emiya.
A great Shirou Emiya crossover fanfic is 'Shirou and the Avengers'. Imagine Shirou in the Marvel Universe. He could project Mjolnir and use Thor's power. His selfless nature would fit well with the Avengers' values. Also, 'Shirou in the Dragon Ball Universe' is fascinating. He might train with Goku and learn ki control, while also showing his own swordsmanship skills against powerful foes in that universe.
There are fanfictions where Shirou's ideals are tested in the Naruto universe. In this world full of ninjas, he might have to reevaluate his way of helping people. Maybe he gets involved in the conflict between the villages and tries to find a peaceful solution, using his unique abilities. It's fascinating to see how his character from the Fate series would interact with the Naruto characters.
One common theme is the exploration of their different personalities coming together in a marriage. For example, Artoria's noble and sometimes aloof nature with Shirou's self - sacrificing and determined personality. Another theme could be how they deal with the challenges of their new relationship in a world full of magical and dangerous elements.
Well, Shirou could form an unlikely alliance with some of the characters in Highschool DxD. Maybe he teams up with Issei and his group. Since Shirou has a strong sense of justice, he could help them in their battles against stronger enemies. He might also teach them some of his combat techniques, like how to better utilize their own powers.
There could be a fanfiction where Shirou Emiya discovers a long - lost family member who is also a powerful mage. The story could revolve around their relationship, how they learn from each other, and how they face challenges together. Or perhaps a plot where he has to use his powers to enter a magical realm and retrieve a powerful artifact to save his world from destruction.
One plot idea could be Dark Shirou in a post - apocalyptic world where he uses his skills to survive and rule a small territory. Another could be his journey to find a way to reverse his dark transformation. Or a plot where he has to face his darker self in a psychological battle within his own mind.
One interesting plotline could be Shirou using his gamer skills to quickly analyze and defeat opponents in the Holy Grail War. For example, he might see the battle scenarios as levels in a game and use strategies he learned from gaming to outwit his enemies. Another could be him leveling up his own abilities in a way similar to how a gamer levels up a character, perhaps unlocking hidden powers within himself that were previously unknown.
You can start by looking on fanfic platforms like Archive of Our Own (AO3). Just search for 'Shirou Emiya' in the search bar and you'll get a list of fanfics related to him. Another option is to check out fanfiction.net, which also has a large collection of fanfics.
The contrast. Shirou Emiya is originally a complex character, and making him an overpowered gamer creates an interesting contrast to his usual self. It's like seeing a different side of him.
One plot idea could be Shirou Emiya finding himself in the world of Fairy Tail and having to adapt to the magic - based society. He might try to use his Reality Marble in unique ways to combat the dark guilds. Another could be him teaming up with Natsu and his friends to take on a powerful, otherworldly threat that has somehow entered the Fairy Tail universe. He could also learn new forms of magic from the wizards in Fairy Tail, like learning how to incorporate Fairy Tail - style elemental magic into his existing abilities.