The fire area is the hardest area in the game by far, the blue ball guys have too much hp making me waste most of my weapon ammo on them, when I got to the dragon I couldn't beat the boss at all because I had no ammo and the dragon was too tanky
Edit: that or you reduce the spawn rate for them because I feel as though too many of them spawn
Edit2: Also the fire projectiles can multi-hit you out of strong spirit without euphoria and I feel like the dragon fires a bit too many projectiles at times