In this fanfiction, the betrayal of Natsu might be the catalyst for a whole new adventure. He could be betrayed by a powerful enemy who has a vendetta against him. This leads to him being thrown into the DxD Highschool world. There, he meets all kinds of characters. Some might be suspicious of him, while others are intrigued. Natsu, with his dragon - slayer powers, would be a force to be reckoned with in this new world. He may have to face off against some of the powerful devils in the DxD universe, and in the process, uncover secrets about his own betrayal and find a way to return to his world and set things right.
The plot could involve Natsu being betrayed by someone close to him, like a guildmate perhaps. This betrayal sends him into a state of shock and anger. When he arrives in the DxD Highschool world, he initially struggles to adapt. However, as he discovers more about this new world, he realizes that there are similarities to his own situation. For example, the idea of loyalty and betrayal exists there too. He could then start to learn from the experiences of the DxD characters and grow stronger, all while plotting his revenge against those who wronged him.
Well, one possible plot could be that Natsu is betrayed in his own world and somehow ends up in the DxD Highschool universe. Maybe he has to deal with the different power dynamics and politics there while also trying to figure out who betrayed him in his original world. He might form new alliances with the characters in DxD Highschool and use his unique abilities to survive and seek revenge for his betrayal.
Natsu, being a fiery and passionate character, would likely have a rather intense interaction with the DxD Highschool characters. He might be initially distrustful due to his recent betrayal. But some of the more friendly characters in DxD, like Issei's group, could try to befriend him. Natsu would probably show off his powers a bit, which would either impress or intimidate the others. And there could be some clashes in personalities, for example, Natsu's straightforwardness against some of the more devious DxD characters.
One possible plot could be that Natsu, being in the DxD High School setting, is betrayed by someone he considered a close friend. Maybe this friend reveals Natsu's secrets to the enemies in the DxD world. As a result, Natsu has to face new challenges alone, all while trying to figure out how to deal with the betrayal and regain his trust in others.
One idea could be a crossover where Natsu finds himself in the world of High School DxD and has to deal with the devils and angels there. He might use his fire magic in unique ways to combat the various threats in that universe.
Well, in a 'Naruto x Greyfia Highschool DxD' fanfiction, perhaps Naruto is a new transfer student in the Highschool DxD. Greyfia could be a popular student there. Naruto's positive and energetic attitude might attract Greyfia's attention. They could start off as friends and gradually develop a deeper relationship. Maybe they get involved in the supernatural battles of the DxD world together, with Naruto using his Rasengan and other jutsu while Greyfia uses her demonic powers. And as they spend more time together, they learn from each other's worlds and values.
One possible plot could be that Naruto is somehow transported to the Highschool DxD universe and meets Gabriel. They might team up to face a common threat that is endangering both the ninja world and the supernatural world of Highschool DxD. Naruto's unique skills as a ninja could be combined with Gabriel's angelic powers in an epic battle against evil forces.
One possible plot could be that Naruto, with his godlike powers, ends up in the world of Highschool DxD. He might join the Occult Research Club and use his unique abilities to protect the club from various threats. His ninja skills and super - powered jutsus could be a huge asset in battles against devils, fallen angels, and other supernatural foes.
One plot idea could be Natsu accidentally ending up in the Highschool DxD world and having to adapt to the different rules and magic systems there. He could make friends with some of the main characters and they could team up to fight a common enemy that threatens both his world and the Highschool DxD world. Another idea is that Natsu's unique brand of magic could be a mystery to the characters in Highschool DxD and they try to figure out how it works while also teaching him about their own powers.
Well, perhaps Erza was tricked into believing something false about Natsu. Maybe she was misled by some enemy who made it seem like Natsu was going to endanger the guild. So, in her sense of duty to protect the guild, she took actions that Natsu perceived as betrayal.
Perhaps she is betrayed in a romantic sense. She falls for someone who then turns out to be using her for their own gain, like getting closer to powerful members of the guild through her. This would shatter her trust in love and make her more guarded in future relationships.
One thing that makes this type of fanfiction appealing is the contrast. Naruto, a character known for his loyalty, is betrayed in his own world. Then he's thrown into the DxD highschool where there's a whole new set of rules and relationships. The harem part means there are multiple characters with different personalities that can have various interactions with Naruto. It's also about seeing Naruto grow and change in this new environment, perhaps learning to trust again through his relationships with the harem members.