The popularity of jenlisa fanfic lies in the huge fan following of Jennie and Lisa. Their real - life friendship and chemistry are so strong that fans are eager to see more of their relationship explored in fictional stories.
Sure. 'The Unspoken Bond' is a great jenlisa fanfic. It beautifully depicts their friendship evolving into something more. The author does an excellent job of portraying their characters and the chemistry between them.
Fanfics basically involve fans creating their own narratives based on the elements of something they love. It can be anything from imagining new adventures for characters to exploring alternate storylines. They're a way for fans to express their creativity and passion for the source material.
In BNHA fanfics, there are often ones that expand on the backstories of minor characters. This gives more depth to the overall BNHA universe. In AssClass fanfics, some might focus on the challenges the students face outside of school while still having Koro - sensei's influence. 'The World Beyond School' is a fanfic that does this well, showing how the students apply what they've learned in class to real - life situations.
It's hard to say they are widely popular. They are likely only popular within very specific, niche communities that are interested in the particular theme related to a cockring. Most mainstream audiences would not be into this type of fanfic.
First, you need a clear idea or concept for your fanfic. Then, decide on the characters and their development. Start writing with an engaging beginning and build a compelling plot.