To develop their relationship realistically, start with them as friends. Have them share common interests like training or exploring the supernatural world. Then gradually introduce moments of deeper connection, like when one saves the other from danger.
Well, there could be a story where Issei gets injured badly, and Ravel takes care of him. During this time, they start to see each other in a new light. It could also be about them participating in a tournament together, and their teamwork and growing bond make them a force to be reckoned with.
One reason for the popularity could be the appeal of the characters Issei and Ravel themselves. Fans who love these characters might be interested in seeing their relationship take on a more romantic or even sensual turn in a lemon fanfic. Also, the lack of such explicit exploration in the official content might drive fans to seek it out in fan - made works. Additionally, the creativity of the fanfic authors in developing their relationship and the scenarios they create can contribute to its popularity.
You can try looking on fanfiction websites like FanFiction.net or Archive of Our Own (AO3). Just search for 'Issei and Ravel' in the search bar on those sites and then filter through the results to find ones that might include a kiss scene.
Finding 'Issei x Ravel' lemon fanfic can be a bit tricky. Some fanfic communities on platforms such as Reddit might discuss or even share links to such works. However, be cautious as not all content may be appropriate or allowed. You could also try searching in relevant fan groups on social media platforms, but again, make sure to follow the rules.
One factor could be the fan base's desire for romantic or intimate moments between the characters. Fans love to see their favorite characters in different scenarios, especially ones that involve some form of affection like a kiss. In the case of Issei and Ravel, it might also be about the potential for their relationship to develop in unique ways that the fanfiction writers can explore. For example, how their personalities interact during and after such a moment. Additionally, the fanfiction gives fans the opportunity to be part of the creative process, adding their own ideas and interpretations to the relationship.
The appeal might be in the unexpectedness. If in the original story their relationship is not that developed towards a kiss, seeing it in fanfiction can be exciting.
One common theme is probably the development of their relationship. It might show how they grow closer over time, from initial acquaintance to falling in love and finally getting married.
You can try searching on popular fanfiction websites like Archive of Our Own (AO3) or FanFiction.net. Just type in the relevant keywords 'Issei Marries Ravel' in their search bars, and you might find some interesting stories.
A common theme could be the development of their relationship. Since it's a fan - created pairing, many fanfics might focus on how they get to know each other better, overcome differences, and grow closer.