Issei would probably be both scared and excited. He's used to dealing with powerful beings, but the Ghost Rider is on a whole different level. He might initially try to fight him out of bravado, but soon realize he's outmatched. Rias would be more cautious. She would see the Ghost Rider as a potential threat to her peerage and would try to figure out his motives before taking any action.
One great Highschool DxD and Ghost Rider fanfiction is 'The Devil's Rider'. It combines the supernatural elements of both universes really well. The main character, who has traits of both a Devil from Highschool DxD and Ghost Rider, goes on exciting adventures fighting various demons and devils. It's full of action -packed scenes and some interesting character interactions.
Ghost Rider's abilities would be a major factor in a Highschool DxD fanfiction. His immortality, for instance, is different from the ways characters in Highschool DxD achieve long - life or near - immortality. In Highschool DxD, it's often through magic or special bloodlines. Ghost Rider, on the other hand, is cursed with immortality. His speed is also something to consider. While there are fast characters in Highschool DxD, Ghost Rider's speed combined with his other abilities like his hellfire and chains would make him a formidable force. He could move through the Highschool DxD world with ease, leaving a trail of destruction or justice, depending on his purpose at the moment.
The clash of personalities. Highschool DxD characters are often flirty, power - hungry, or have their own personal agendas. Ghost Rider, on the other hand, is a force of vengeance. When they interact in fanfiction, it leads to some really interesting character dynamics. It can be like a devil trying to manipulate Ghost Rider for their own gain, but Ghost Rider's unwavering sense of justice won't allow it.
Well, the plot could involve a character from Highschool DxD making a deal that accidentally summons the Ghost Rider. The Rider then starts to hunt down evil in the Highschool DxD world, which includes some of the more malevolent devils and fallen angels. This would force the different factions in Highschool DxD to either side with the Ghost Rider or oppose him. And the main character of Highschool DxD might be caught in the middle, trying to figure out how to deal with this new and extremely powerful entity.
The presence of Ghost Rider in a Highschool DxD fanfiction would likely create a lot of chaos. His powers are far beyond what most characters in Highschool DxD are used to. He could easily become a major disruptor of the power balance. For example, his Penance Stare would be a huge threat to the devils and other supernatural beings in the Highschool DxD universe. His hellfire could also cause massive destruction. However, it could also lead to some interesting alliances. Maybe some of the good - natured characters in Highschool DxD would see him as an ally against the more malicious forces.
Well, it could be about a kamen rider who enrolls in the highschool from DxD. Maybe he has to use his kamen rider powers to fight off devils or other supernatural threats that target the school. He could also form an unlikely alliance with some of the characters from DxD, like Issei and his friends.
There are quite a few out there. Some focus on how the power - ups in Kamen Rider could be translated into the DxD power system. For example, a fanfic might have the Kamen Rider's transformation devices being mistaken for powerful artifacts in the DxD world, leading to all sorts of comical and action - filled situations. You can usually find these on popular fanfiction websites by using relevant tags.
Issei would probably be the first to want to fight Thanos. He's always eager to prove himself and protect his friends. He might initially underestimate Thanos due to his own growing power and confidence, but soon realize how powerful Thanos really is. Rias would be more cautious. She would likely try to gather information about Thanos first and then formulate a plan to either fight or negotiate with him.
Issei, being the hot - blooded character he is, would probably be excited to meet someone as powerful as Naruto. He might challenge Naruto to a friendly spar at first, hoping to learn from him and test his own strength. And as he gets to know Naruto better, he could start to see him as a brother - in - arms, especially if they face common enemies together.