Naruto and Rias are bound to be the central characters. Naruto with his determination and power, and Rias with her leadership and magic. But we can't forget about the other members of Rias' peerage. They might have different reactions to Naruto being adopted. Some could be welcoming, while others might be a bit skeptical at first. And Naruto's own comrades from Konoha might also be relevant, perhaps in flashbacks or if they somehow cross over into Rias' world.
Definitely Naruto and Grayfia. Naruto is the main protagonist who has his own story and growth arc. Grayfia is the one who changes Naruto's life by adopting him. She could be a noble or a powerful mage. There may be other characters such as servants or comrades of Grayfia who are initially skeptical of Naruto but later come to accept him. And of course, there could be antagonists. Maybe there are some rivals in Grayfia's world who don't like the idea of an outsider like Naruto being in their midst and they try to cause trouble for him.
Obviously, Naruto would be one of the main characters. He brings his ninja skills, his strong will, and his unique personality. And from the Rias family, Rias herself would be a main character. She has her own leadership within the family and her devil powers. Also, her peerage members could also be important characters as they interact with Naruto.
The Raikage, Ay, would also interact with Naruto. He might be hesitant at first about Killer Bee adopting Naruto, worried about potential problems. But as Naruto shows his strength and loyalty, Ay could start to see Naruto as an asset to the village. And of course, Naruto's friends from the Hidden Leaf Village might come to visit or have some sort of communication with him, like Sakura and Shikamaru. They could be worried about Naruto living in a different village but also be proud of his new experiences.
Obviously, Harry Potter is the central character. Then there are the Malfoys - Lucius, Narcissa, and Draco. Hermione and Ron might also be involved, perhaps as characters who are initially suspicious of Harry's new situation but later come to understand it.
Naruto and Rias are the central characters. Naruto is known for his never - give - up attitude and his array of ninja techniques. Rias is a complex character with her own political and social standing in the devil world. However, in some fanfictions, other characters from both the Naruto and High School DxD universes can become important. Kiba from Naruto might befriend Naruto in the new world and help him understand the devil society better. And from the High School DxD side, Akeno, Rias' friend, could play a role in either supporting or testing Naruto's relationship with Rias.
Obviously, Harry Potter himself would be a main character. Then, there would probably be members of the Potter family, like his adoptive parents. Also, characters like Dumbledore might still play important roles as he often has a hand in Harry's life.
Obviously, Harry Potter himself is a main character. And then there would be the Daedra who adopt him. Depending on which Daedra are involved, they would each have their own personalities and motives. For example, if it's a powerful and manipulative Daedra, it could be a major source of conflict for Harry.
The two main characters are Naruto and Rias. Naruto, with his ninja skills and his journey of growth in his original story. Rias, whose actions towards Naruto are the central focus of this fanfiction. There could be side characters like Naruto's friends from his world who might try to find out what happened to him, or characters related to Rias who could either support or oppose her decision to leave Naruto to die.
The main characters are Naruto and Rias. Naruto is known for his rasengan and his ability to make friends and inspire those around him. Rias, on the other hand, is a leader among devils and has a group of loyal servants. In this fanfiction, with Rias being pregnant, their relationship and how they handle this new situation become the central focus of the story.
In a fanfiction where Naruto is adopted by Rias, there would be a significant cultural clash at first. Naruto comes from a world of shinobi where loyalty to the village is key, while Rias's world has its own set of values regarding loyalty to the devil clan. However, Naruto's growth potential is huge. His rasengan could potentially be modified with the magic in Rias's world. He could also teach some of his ninja training methods to the members of Rias's peerage, enhancing their combat capabilities. And his experience with fighting powerful enemies in his own world would give him an advantage when dealing with threats in Rias's world.