Goku's powers are on a completely different level compared to most characters in Highschool DxD. His Saiyan abilities like Super Saiyan transformations give him incredible strength, speed, and energy projection. In contrast, the characters in Highschool DxD mainly rely on magic and their devil or angelic powers which, while powerful, are not on the same scale as Goku's in terms of raw power. For example, Goku could easily defeat most low - level devils with a single punch in his base form.
Issei would be very likely. Since Issei is the main character in DxD, his curiosity and his own pursuit of power would make him interested in Goku. They could train together and learn from each other's abilities. Also, Rias would interact with Goku. As a powerful devil, she would be intrigued by Goku's power and his different way of approaching battles.
Yes, there are some great ones. You can start by looking on fanfiction websites like FanFiction.net or Archive of Our Own. Just search for 'Goku Highschool DxD' and you'll find a variety of stories with different plotlines and interpretations.
Well, there are several common themes. First, there's the clash of cultures. Goku comes from a very different background than the characters in Highschool DxD, so how they interact and understand each other is a big part of many stories. Then there's the theme of self - discovery. Goku might discover new aspects of his powers or his personality while in this new world. Additionally, the idea of protecting the new world he's in is also quite common. Since he has a heroic nature, he would likely want to keep the Highschool DxD world safe from any threats, whether they're new to him or familiar from his own universe.
Goku's powers in a High School DxD fanfiction would be a game - changer. His ki attacks could be on a level that could potentially destroy entire areas in the DxD universe. His martial arts skills are also top - notch. In a fight, he would use his speed and agility to dodge attacks and then counter with his powerful punches and kicks. His transformation abilities, like Super Saiyan, would be a shock to the characters in DxD. They might not have any means to counter such a huge boost in power.
One possible plot could be that Goku is somehow transported to the DxD universe. He might initially be confused by the different rules and magic there. Then, he could start training with the devils and angels, sharing his own fighting techniques. This could lead to some epic battles where he combines his Saiyan powers with the unique abilities in the DxD world.
After Dios death in a fanfic, his followers could split into different factions. Some might realize the wrongdoings of their former leader and try to make amends, while others could become more radical in their beliefs, vowing to carry on Dios' legacy in a more extreme way. The fanfic could also explore the emotional turmoil of those who were close to Dios, like his family or closest aides.
One interesting aspect could be the unique interpretations of Naruto characters in a 'dios' (presumably divine or god - like) context. It might show Naruto with enhanced powers or a different role in the story, like a protector of a more divine nature.
You might have to complete specific quests or challenges within the game to obtain Dios Diary. It could involve interacting with certain characters or exploring hidden areas.
One idea could be Son Goku being transferred to the Highschool DxD world as an exchange student. He could be confused by the different rules and the presence of devils, angels and fallen angels. But his combat skills would surely make him a force to be reckoned with in the Rating Games.