This story is a derivative fanfiction based on the PS4 action RPG Bloodborne. Like FromSoftware's Souls series, Bloodborne offers almost no explanation of its story beyond a few hints about the main plot. Much of its worldbuilding has to be pieced together and analyzed from item descriptions. For many fans, alongside the challenge of its unforgiving gameplay, this open-ended world that invites exploration and speculation is one of the game's biggest appeals.
I actually wrote a full-length adaptation of the Dark Souls series before Bloodborne came out. At the time, I poured my interpretation of Dark Souls' story into a classical fantasy novel of over 400,000 words. Unfortunately, in my effort to stay faithful to the source, most of the story followed the game's conquest path. It wasn't until the final chapter that I finally broke free of the framework laid down by the prevailing theories. After that experience, I decided to begin this Bloodborne fanfiction with a prequel, and, in the spirit of a fantasy horror story, fill in one premise the game gives the player: I must go to Yharnam.
In any case, although this is a fanfiction, it should be accessible even if you aren't familiar with the game. As with my earlier work, Dark Souls: The Story of the Nameless, I won't assume any prior knowledge from fans, so feel free to read this simply as a fantasy horror story.
Note: If you are only interested in the game's original story, I recommend starting from Chapter 3.