While playing Bloodborne: The Old Hunters DLC, you will need to find a couple of items in order to proceed through the DLC. These items include the Brain Fluid, the Balcony Key, and the Holy Moonlight Sword.
This guide details all the locations where you can find the Brain Fluid, the Balcony Key, and the Holy Moonlight Sword:
There are a couple of locations in the Research Hall where you can find the Brain Fluid. If you head to the third floor, you will come across a Hunter and a Brain enemy which when killed should drop the Brain Fluid – use the elevator to reach the area.
Another location where you can find the Brain Fluid is at the very top where you can access the rafters. You need to head over to the center of the platform and raise it to the very top in order to find the Brain Fluid.
After acquiring 2x Brain Fluids, head to Saint Adeline and interact with her to acquire the Blood of Adeline for the Brain Fluid. Once obtained, head back to the Hunter’s Dream and return after a while.
Once again head back to Saint Adeline and speak with her again to acquire the Balcony Key in exchange for another Brain Fluid. It is worth noting here that you may have to head out of the area and return if she does not ask for the Brain Fluid.
Holy Moonlight Sword
For this, you need to defeat Ludwig and equip the church gear. Once done, you simply need to check left side of Ludwig’s head in order to acquire the Holy Moonlight Sword.
This is all we have on acquiring the Brain Fluid, the Balcony Key, and the Holy Moonlight Sword in Bloodborne: The Old Hunters DLC. If there is something else you would like to know, make sure to let us know in the comments section below!