I'm not sure specifically which 'issei' you are referring to in the light novels. There are many characters named Issei in different works. Without more context, it's difficult to determine if this character has such interactions in the light novels.
To determine if an 'issei' has cheated on fanfiction, we would need to look at the specific fanfiction in question. Different fanfictions have different storylines and character developments. Maybe in some very niche or specific fanfiction, there could be a situation where an issei - like character is involved in cheating, but it's not a common or known occurrence in general fanfiction.
Light novels cover a wide range of genres and themes. If the 'issei' is from a series that is known for its action - adventure or slice - of - life aspects, it's less likely to have sexual content directly related to the character. However, if it's from a more romantic or adult - targeted series, there could be a possibility, but still, we need more details about the specific work.
Issei's strength in the light novel is significant. His power increases through training, experiences, and unique opportunities, making him a formidable character.
The 'Respect Issei' light novel likely focuses on the character Issei and how respect plays a role in his story. Maybe it shows different characters respecting Issei for his unique qualities, like his strength, determination or kindness. It could also be about Issei earning respect in a particular world or community within the story.
You could try 'Passions Beyond Bounds'. The MC's sexual experiences are woven into a complex plot. But keep in mind that these scenes are intended for a specific audience seeking a more adult-oriented story.
Well, there are some light novels with such elements. 'Goddess' Desires' is one where the relationship between the MC and the goddess gets quite intense. However, these kinds of themes can be quite niche.
Since I'm not very familiar with this specific light novel, I can only guess that Issei is surely one of the main characters. There might be some friends or allies of Issei, like a mentor figure who helps him on his journey to earn respect, or a rival who initially doesn't respect him but later changes their view.
In the light novel, Issei might propose to Rias in a very Issei - like way. He could use his unique charm and determination. Maybe he would do it in a moment of victory or after a deep emotional conversation. It would probably be filled with his passionate feelings for Rias and his eagerness to be with her for the rest of their lives.