I haven't read this particular 'blow to katsuragi senran kagura fanfic' specifically. But generally, in fanfics related to Senran Kagura, they often explore the characters in more depth. Maybe this one focuses on Katsuragi and some kind of 'blow' could refer to an action, event or even a metaphorical concept within the story.
Rather than seeking adult fanfiction, you can look for fan - made stories that delve into Misato's leadership, her friendship with other characters, or her backstory. These types of fanfictions can be found on various fanfiction platforms by using appropriate filters.
Well, Keima Katsuragi is known for his otaku - like nature. He is obsessed with video games and 2D girls. This characteristic plays a major role in the visual novel as it drives many of the storylines. For example, his knowledge and passion for gaming often help him in various challenges he faces within the game - world - like scenarios of the visual novel.
Another important character is Haqua. She has her own motives and goals within the story. She sometimes competes with Keima or gets involved in his plans. Her presence adds more depth and complexity to the plot. There are also some schoolmates of Keima who play important roles in creating the social environment of the visual novel and influencing Keima's actions and decisions.
As of now, the Genshin manga is not finished. The story is still evolving and there's more to come for fans to enjoy. The creators are taking their time to develop a rich and engaging narrative.
There's no definite answer yet. It might continue if there's enough demand and the creative team has more story to tell. But it could also stop if they feel they've completed the story arc.