Rias could be a main character. She has a strong connection with Issei and in a fanfiction about him as the Prince of Darkness, she might play a role in helping him control his new power or deal with the political ramifications of his new status.
In many Issei in the Darkness fanfictions, Issei often undergoes character development. He might face new challenges that are different from the original story. For example, his relationships with other characters can be re - defined. He could form stronger bonds with some characters while having more complex rivalries with others. This makes the fanfiction interesting as it gives a fresh perspective on the character.
Sadly, I have no idea who the author of 'issei is the darkness fanfiction' is. Fanfiction can be created by many different people all over the world, and without more context or research, it's impossible to determine the author.
Since it's a fanfiction about Issei and 'the darkness', it might be a story that delves into the darker aspects of Issei's character. It could be set in a world where 'the darkness' is a powerful and menacing presence. Issei could be on a journey to either embrace or overcome this 'darkness'. There could be other characters involved who either help or hinder him in this exploration of the 'darkness' within and around him.
One plot idea could be Issei facing a powerful new enemy that challenges his status as the Prince of Darkness. He might have to gather allies from different realms and use his unique powers in new ways.
The character of Issei already has a large fan base from the original work. When combined with the concept of the Darkness, it allows for crossovers and mash - ups with other concepts or characters that fans might be interested in. For example, there could be a story where Issei in the Darkness encounters a character from another popular series, creating a whole new dynamic.
Many of the powerful noble houses would be his enemies. For example, the Lannisters, who are already in a struggle for power. They would not want to share or lose their power to the Prince of Darkness. And the Tyrells, who are also politically astute and would view the Prince as a threat to their influence and the stability of the Seven Kingdoms.
Well, in a 'naruto prince of darkness fanfiction', it might explore a version of Naruto who has been corrupted in some way. It could show how his relationships change as he becomes this so - called 'prince of darkness'. For example, his friends might be afraid of him or try to save him from the darkness that has consumed him. It could also introduce new characters who are associated with the dark side and interact with Naruto in different ways.
No. Since adult fanfiction often contains inappropriate content, it is not promoted or widely popular. Moreover, 'Prince of Darkness' is a rather specific topic. Usually, fanfictions about more mainstream and positive characters or stories are more likely to be popular.