In this fanfiction, it could be that Shirou is brought into the Sekirei world by some sort of magical accident. He then has to navigate the complex relationships and rules of this new world. He might find himself at odds with some of the established Ashikabi and Sekirei, but also make some unexpected alliances, all while trying to figure out how to get back to his own world if possible.
Well, it could be about Shirou getting involved in the Sekirei battles. Maybe he uses his skills from his original story to help or compete in the Sekirei world. For example, his sword - fighting abilities might give him an edge in combat against other Sekirei or their Ashikabi.
The plot might center around Shirou becoming an Ashikabi. He could have a unique way of bonding with the Sekirei, perhaps using his strong sense of justice and determination. His Sekirei might be special too, having powers that complement his own skills, and together they strive to reach the top in the Sekirei Plan.
It could be a powerful Sekirei who sees Shirou as a threat to the Sekirei Plan. This Sekirei might be very traditional in their views and not like the idea of an outsider like Shirou interfering.
One common theme is the clash of two different worlds. Shirou comes from the Fate universe with its own set of rules, magic, and values, while the Sekirei world has its unique system of Sekirei, Ashikabi, and battles. Another theme is adaptation. Shirou has to adapt to the new rules and environment of the Sekirei world. For example, understanding how to form bonds with Sekirei as an Ashikabi.
Maybe Gohan is summoned to the Sekirei world for some unknown reason. He then befriends some of the Sekirei and starts to train them in martial arts. This would not only help the Sekirei in their battles but also change their perspective on strength. Gohan's kind heart and strong sense of justice would lead him to oppose the Ashikabi system if he finds it unjust, and he'd try to find a new way for the Sekirei to coexist peacefully.
A plot could center around a lost Star Wars character ending up in the Sekirei world. This character, perhaps a young Jedi in training, has to find a way back home. In the process, they befriend a Sekirei and start to understand their way of life. Meanwhile, back in the Star Wars galaxy, the Sith sense an unusual power shift due to the connection between the two worlds. They send agents to the Sekirei world to investigate and try to disrupt the harmony there. The young Jedi and their Sekirei friends must then work together to stop the Sith and also find a way to reopen the portal to send the Jedi home.
One popular Shirou is a Sekirei crossover fanfiction might be 'Shirou's Sekirei Adventure'. In this type of crossover, Shirou's character traits from his original story, like his determination and swordsmanship skills, could blend interestingly with the Sekirei world's unique elements such as the Sekirei battles and the concept of Ashikabi. Another one could be 'Shirou in Sekirei's World'. These crossovers often explore how Shirou would adapt to the Sekirei universe and how his presence might change the existing storylines in the Sekirei world.
Well, perhaps the Sekirei start to appear in Hogwarts. Some students might accidentally bond with them. Harry could be in a dilemma as he tries to balance the chaos this causes in the school with the need to keep the wizarding world safe from external threats like Voldemort. The Sekirei's abilities could add a new dimension to the magical battles in the Harry Potter universe.
One possible plot could be that the Straw Hat crew sails to the world of Sekirei. Luffy might be intrigued by the concept of Sekirei battles and try to participate in a friendly way. Maybe Zoro would find some Sekirei with interesting sword - fighting skills and have duels with them. And Nami could be interested in the economic aspects of the Sekirei world, like how they trade resources or manage their finances.
The plot could involve Naruto characters somehow ending up in the Sekirei world. Maybe Naruto, with his never - give - up attitude, would get involved in the Sekirei battles. He could use his ninja skills to protect the Sekirei from other dangerous forces. And perhaps some of the Sekirei would be intrigued by Naruto's chakra and his unique abilities.
Well, Shirou in crossover fanfiction often shows his tenacity. No matter how strange or difficult the new world he is in, he doesn't give up easily. In a crossover with the Digimon world, he faces many challenges but keeps fighting. His loyalty is also a big part of his character. If he makes friends in the new world, he will be loyal to them and protect them at all costs. And his growth as a character is interesting. He may start with his basic set of skills from his original world, but as he experiences new things in the crossover world, he evolves, both in terms of his combat abilities and his understanding of different cultures and values.
In this type of fanfiction, it could be that Naruto enters the Sekirei world during one of his training missions gone wrong. He is neglected by the Ashikabi (the Sekirei masters) at first because he doesn't seem to have any Sekirei - like powers. However, Naruto's strong will and determination attract a Sekirei who is also different from the others. They start to train together, Naruto teaching the Sekirei about ninja values like loyalty and perseverance. As they progress, they start to change the perception of what it means to be strong in the Sekirei world, and Naruto becomes an important figure despite the initial neglect.