The crossover could also involve a scenario where Rias is somehow transported to Sephiroth's world. She would be completely out of her element in a world filled with so much chaos and destruction. Sephiroth might see her as a curiosity at first. But as she shows her tenacity and her own brand of power, he starts to take her more seriously. They could end up teaming up against Sephiroth's enemies, like Shinra, with Rias using her devilish abilities and Sephiroth his superhuman combat skills.
In this crossover fanfiction, perhaps Sephiroth is brought into Rias' world. Rias' peerage might initially be very wary of Sephiroth. However, his skills in combat and his knowledge of magic could prove useful. Rias could see potential in him and try to sway him from his darker path. They might go on adventures together, facing off against powerful devils and other threats, and in the process, a unique bond forms between them that is a mix of friendship and mutual admiration.
A potential storyline could be a battle - royale - style plot. Sephiroth and Rias are forced to participate in a tournament in a neutral dimension. They have to fight against various powerful opponents. Along the way, they learn about each other's fighting styles and motives. This could lead to an alliance between them as they realize they have a better chance of winning together. And in the end, they might face a final boss that is a threat to both their existences.
Well, perhaps in this crossover, Sephiroth is a rogue ninja from a far - off land that has powers similar to his in the Final Fantasy world. He starts causing destruction in the Hidden Leaf Village. Naruto, being the hero, decides to face him. Along the way, they discover that their powers have some strange similarities. For example, Sephiroth's sword techniques could be compared to some of the advanced sword - using ninja in the Naruto world. And they might end up having to team up against a greater evil that emerges because of Sephiroth's arrival.
Well, it could be about Sephiroth using his incredible combat skills from Final Fantasy in the world of Attack on Titan. Maybe he teams up with the Survey Corps to take on the Titans. He might use his Masamune sword to slice through the Titans' nape with ease, bringing a new level of badassery to the fight against the Titans.
One possible plot could be that Sephiroth, with his superhuman abilities and thirst for power, somehow ends up in the Marvel universe. The Avengers initially mistake him for a new, extremely dangerous threat. They try to fight him but quickly realize his power level is off the charts. Then, they might try to find a way to send him back to his own world while Sephiroth, intrigued by the power sources in the Marvel universe like the Infinity Stones, tries to get his hands on them.
It could be a story full of epic battles. Imaginary Sephiroth is often associated with great power and Lightning is also a strong character. They might start as rivals, each thinking their own way is right in saving the world or achieving some grand goal. Their first encounter could be filled with tension as they size each other up, not sure whether to fight or cooperate.
Well, in a 'Naruto is Rias' brother' fanfiction, there would be a lot of potential for character development. Naruto, being from a world where he had to fight for his place and for the safety of his village, would bring that same determination to protect Rias and her friends. He might be shocked at first by the devil society's hierarchy and customs, but would gradually find ways to fit in and make changes. Rias, on the other hand, would have a powerful and loyal brother by her side. They could face off against common enemies, like other devils who oppose Rias' ideas or angels who see Naruto as an unknown and dangerous element. The fanfiction could also explore their family backstory, how they were separated in the first place and what it means for them to be reunited now.
One idea could be that Sephiroth somehow gets transported to the feudal era of Inuyasha. He might initially be seen as a great threat due to his power. But as the story progresses, he could form an unlikely alliance with Inuyasha and his group against a common enemy, like a powerful demon that is even more menacing than any they've faced before.
Well, their story could be really interesting. Naruto, with his determination and strong will, and Rias, being a powerful devil. They might face challenges from both the ninja world and the devil realm. Maybe Naruto would teach Rias some of his ninja techniques, and Rias could introduce Naruto to the complex politics of the devil world. Their marriage could be a bridge between two very different universes, leading to all kinds of adventures and new friendships.
In a Naruto and Rias Gremory fanfiction, Naruto's chakra system could interact in interesting ways with the magic in Rias's world. His ability to control and manipulate chakra might be seen as a form of power that the devils would either fear or try to understand. Rias, on the other hand, could introduce Naruto to the political and social aspects of her world. They could also exchange combat techniques, with Naruto showing the devils how to move with the speed and stealth of a ninja, and Rias's group teaching Naruto some devil - specific magic that could enhance his abilities in different ways.
One popular sephiroth crossover fanfiction might be one where he crosses over into the Final Fantasy VII Remake universe in a different timeline. This can create interesting storylines as he interacts with the new versions of characters.