A potential plotline could involve a magical accident that fuses the two worlds together. Shirou, being the heroic type, steps up to help restore order. He might encounter characters like Dumbledore and share his own experiences and knowledge of magic. His relationship with Harry could be an interesting aspect, as they both have a sense of justice and a willingness to fight for what's right. Shirou could also face challenges from the Death Eaters, who might see his different kind of magic as a threat. As he tries to find a way back to his own world, he becomes deeply involved in the fight against Voldemort, using his skills and determination to make a difference in the Harry Potter universe.
Perhaps Shirou could be mistaken for a new kind of wizard in the Harry Potter world. His different approach to magic, which is more about projection and his own ideals in 'Fate/stay night', could cause some confusion and also new opportunities. He could end up teaching some of the Hogwarts students his unique magic techniques, which could then be used against the dark forces. And there could be a struggle within him as he tries to adapt to the new magic system while still holding onto his own values.
One possible plotline could be Shirou finding himself magically transported to the Harry Potter world. He might use his skills in magic and combat from his own world to help Harry and his friends in their battles against Voldemort. For example, Shirou's ability to project weapons could be a unique advantage in the wizarding world.
The 'harry potter is op shirou emiya fanfiction' might be a creative blend of two different fictional universes. Shirou Emiya is known for his combat skills and determination in the Fate series. In this fanfiction, within the Harry Potter setting, he could be OP perhaps by having his unique magecraft abilities that are not typical of the magic in the Harry Potter world. For example, his projection magic could give him an edge over the normal spells used by wizards. This might lead to interesting plotlines like him facing off against Voldemort or helping the Hogwarts students in a way that defies the normal rules of their magic. It could also be a story about how he adapts to the new magical environment while still maintaining his OP status.
One possible plotline could be that Ichigo somehow gets transported to the Harry Potter world. He might use his Soul Reaper powers to fight against the dark wizards. Maybe he helps Harry and his friends in a battle at Hogwarts by using his Zanpakuto skills.
One plotline could be Moriarty infiltrating Hogwarts as a new teacher. He could secretly be plotting to steal powerful magical artifacts while also manipulating the students and staff. Harry and his friends would start to notice strange things happening around the school and suspect the new teacher. Another could be that Moriarty teams up with Voldemort, combining their evil minds to take over both the wizarding world and the Muggle world. This would put Harry in an even more difficult situation as he has to face two powerful villains at once.
One potential plotline could be that Harry discovers he has a bijuu sealed within him. This could explain some of his strange powers or abilities that are not accounted for in the original series. As he grows older, he has to learn to control this bijuu power, while also dealing with the usual threats in the wizarding world like Voldemort.
I'm not entirely sure if it's a widely popular concept. Fanfiction can be quite diverse, and while there are many crossovers, this specific one might be more niche. It depends on the overlap between the 'Harry Potter' and 'Fate/stay night' (where Shirou Emiya is from) fanbases.
One possible plotline could be Shirou finding himself in Westeros and using his skills as a swordsman to get involved in the power struggles. Maybe he becomes a knight in someone's service.
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.
Searching for this fanfiction can be a bit of a hunt. As I mentioned before, AO3 and FanFiction.net are your best bets. But you should also be aware that sometimes, the title might be slightly different due to things like formatting or the author's own creative liberties. So, when you search, try different combinations of the words. Additionally, some smaller, more niche fanfiction communities or blogs dedicated to either the Harry Potter series or the Fate series might also host or link to this fanfiction. You can use search engines like Google and type in the title along with keywords like 'fanfiction' and the relevant series names to increase your chances of finding it.
Well, one possible plot could be that Shirou wakes up one day as a girl and has to deal with all the new physical and social changes. His friends might be really confused at first, like Saber who would be very surprised to see her master in a different form. Shirou, now as a girl, might struggle with things like wearing dresses and having different hormonal emotions. And he would have to face enemies in this new form too, which could lead to some really interesting battle scenes where his opponents underestimate him because he's now a girl.
A plot could involve Shirou being transferred to the Highschool DxD school. He quickly catches the attention of Rias and her peerage. His different style of combat and his unwavering determination might lead to some friendly rivalries within the group. He could also introduce some new concepts of magic that the DxD characters have never seen before, like his ability to reinforce objects. And he may find himself in the middle of the power struggles between the different factions in this new world.