In some cases, it could be that the author of the fanfiction simply wants to explore a different narrative where Rias is not the 'perfect' character she is often portrayed as in the main series. They might want to create a more complex or alternative view of the Naruto DxD universe by highlighting what they see as flaws in Rias's character.
I'm not sure specifically about 'naruto rias bashing fanfiction' being popular. There are so many fanfictions out there that it's hard to single out ones that are bashing a particular character as being popular. However, in general, if a fan has a strong opinion about a character like Rias, they might write a story that gets some attention within their niche community, but it may not be widely known outside of that.
Well, 'naruto rias bashing fanfiction' could be stories where the writer doesn't like Rias for some reason and decides to create a narrative that shows her in a bad light. It might be that the writer thinks Rias' actions or personality traits don't fit well with their view of how a character should be. And when combined with Naruto, perhaps they are using elements from Naruto's world to further emphasize the flaws in Rias as they see them. Maybe they are comparing her unfavorably to Naruto's values or the way Naruto's world works.
A common theme could also be her role as a leader. Fanfiction authors might write about her being a bad leader, making wrong decisions that lead to negative consequences for her group. This could be a way for the author to explore different leadership styles and show how things could go wrong under Rias's leadership.
Some people might write such bashing fanfiction because they prefer other characters or storylines over Naruto, Rias, and Issei. Maybe they want to create a different narrative where these characters don't overshadow their favorites. It could also be a form of creative expression to explore how a story would be different without them.
One common plotline could be Naruto being extremely powerful, like a god, and outshining Rias in various challenges or battles. For example, in a tournament setting where Naruto's unique abilities completely overshadow Rias' powers. Another could be Naruto using his godlike status to reform or change the world in which Rias exists, causing her to be in a position where she has to adapt or face difficulties.
For the Naruto fandom, bashing fanfiction could potentially turn some fans away from the overall fanfiction community if they feel that their beloved character is being unfairly targeted. In the case of Rias and Issei's fandoms from High School DxD, it could create a stir as well. Some fans might engage in debates with the writers of the bashing fanfiction, trying to defend the characters. This can lead to both positive and negative interactions within the fandoms. On one hand, it can spark discussions about the characters' qualities, but on the other, it can also lead to a hostile environment if not handled properly.
The main characters are Naruto and Rias. Naruto is the godlike character. His role is often to be the overpowered force that challenges or opposes Rias. He might use his incredible powers to put Rias in difficult situations. Rias, on the other hand, is the character who is often on the receiving end of Naruto's actions. She may be portrayed as an antagonist or at least someone who has to deal with Naruto's godlike presence.
One possible plotline could be that Naruto is transported to the Highschool DxD world and immediately notices Rias's overbearing attitude. He decides to oppose her and starts to gather allies among the other students and characters who are also fed up with her ways. As a result, a power struggle ensues between Naruto and Rias.
Well, it could involve Naruto characters being thrown into the Highschool DxD universe and having some sort of conflict with Rias. Maybe Naruto's skills and values clash with Rias's actions or leadership in the story. For example, Naruto might see her as too power - hungry or not treating her underlings fairly.