In this fanfiction, Naruto might show his jealousy in his typical brash way. He could be all fired up and ready to challenge the person who is making him jealous. Rias, on the other hand, would be more calculating in her jealousy. She might use her devilish powers and influence to subtly drive a wedge between the person causing the jealousy and the object of her affection. They could end up teaming up to get rid of the 'competition' in a rather comical or intense way depending on the tone of the fanfiction.
A simple plot could be that Naruto is invited to a party in the world of High School DxD. Rias sees Naruto getting along really well with Koneko. Since Koneko is one of her servants, Rias gets jealous. Naruto, in turn, notices that Rias is being a bit too friendly with Sasuke who has also somehow ended up in this world. So Naruto gets jealous too. This starts a chain of events where they both try to outdo each other in getting the attention of their respective 'rivals' attention in a rather childish but funny way.
They would likely start with some mutual curiosity. Naruto would be intrigued by Rias's devilish appearance and powers, while Rias would be interested in Naruto's ninja abilities. They might exchange stories about their respective worlds, with Naruto talking about his village and his friends, and Rias sharing about the devil society. Interaction could also involve sparring sessions to test each other's strength.
One possible fanfiction idea could be that Rias' sick brother is a key factor in a power struggle within their supernatural world. Naruto, being an outsider with his own set of skills and values, could get involved. Maybe he forms an alliance with Rias to protect her brother from those who would use his illness to their advantage.
Definitely. The concept of combining different fictional universes in fanfiction is quite common. In a 'Naruto is Rias' Familiar' fanfiction, we could expect to see Naruto's ninja skills and powers being incorporated into the world of High School DxD. Maybe Naruto would use his shadow clone jutsu in battles in the DxD universe or his rasengan against some of the devils. It could also explore how Naruto, with his strong sense of justice and loyalty, would interact with Rias and the other characters in her peerage.
It's quite possible. Fanfiction writers often come up with interesting and unexpected concepts. Since Naruto and the world of Rias have their own distinct fan bases, combining them in a story where Naruto is a fan of Rias can add a new and exciting twist. You could also check fan - run forums dedicated to either Naruto or High School DxD to see if anyone can point you in the direction of such a fanfiction.
One possible reason could be that the storylines in the fanfiction are focused on different aspects or relationships within the fanfic's universe. Maybe the author wants to explore other characters' interactions more deeply and Naruto just doesn't fit into those particular plotlines they have in mind.
If Naruto kills Rias in a fanfiction, it might be due to a misunderstanding. Naruto is known for his strong sense of justice. Perhaps in this fanfic, Rias is misrepresented as a threat to Naruto's world or his friends. But it's still quite a shock as they are from different fictional universes with their own moral compasses.
In many fanfictions, the idea of Naruto and Rias being married is quite interesting. It often involves combining the elements from their respective universes. For example, Naruto's ninja skills and Rias' devil powers could create a unique dynamic in their relationship. Maybe they would face challenges together, like protecting their family from threats that come from both the ninja world and the devil realm.
In some fanfictions, Naruto can be made into Rias' boyfriend through creative writing. Fanfiction allows for crossovers between different fictional universes, and writers can imagine unique relationships. However, in the original Naruto and High School DxD (where Rias is from) storylines, there is no such relationship.
One possible fanfiction idea could be that Naruto and Rias, as twins, grow up in a world where they have to balance their different powers. Naruto with his ninja skills and Rias with her devil powers. They could learn from each other and use their combined abilities to face various challenges.