Interesting idea here, mixing synthwave aesthetics (especially the soundtrack) and medieval fantasy. Reminds me of a browser game based on a RPG Maker 2000 game about vampires I played in the mid-2000s.
Only got to 4 blood vials with regular playing, then messed around and saw that just harvesting humans until you have 500 blood on day one and turning them into 5 blood vials was enough to beat the game, even escaping the Vatican that way. ;)