The amygdala is important in novel experiences. It helps in processing emotions related to new situations. For example, when you encounter a new place, the amygdala may trigger feelings of curiosity or caution.
One way is to base it on the existing blood - related mechanics in the game. Maybe a character discovers a new form of blood transfusion that has the power of 'Blood for Blood'. They could use it to either heal themselves by taking the blood of their enemies or gain new abilities. This would add an interesting twist to the fanfic and stay true to the game's themes.
The story of Bloodborne progresses through exploration and combat. You, as the hunter, will venture into different parts of the city. There are many hidden paths and secrets. When you encounter enemies and bosses, it's not just about the fight. Defeating them often gives you more knowledge about the world. Also, the items you pick up, like blood vials and runes, can sometimes have descriptions that hint at the larger story. The side - quests you take from the various NPCs also contribute to the overall progression of the story. You gradually piece together the history of Yharnam, the significance of the blood, and the role of the Great Ones.
First, you need to know both universes well. Understand the powers, characters, and settings in Naruto and Bloodborne. For example, in Naruto, chakra is a fundamental element, while in Bloodborne, blood and the hunt are central themes. Then, come up with an interesting plot that combines these elements in a unique way. It could be a simple crossover where characters meet, or a more complex story where the two worlds' rules start to blend.