I'm not sure specifically as it depends on the particular fanfiction. It could be about the backstory of Godric's maker in the context of some fictional universe. Maybe it details how they came to be, their powers, and their relationship with Godric.
As I haven't read it, I can't say for certain. But likely the main character would be Godric's maker. There may also be Godric himself, depending on how the story is structured.
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.
There is a Genshin Impact manga available. It brings the game's world to life on the page with beautiful art and engaging storylines. It's a great companion to the game.