This Ash of War provides your weapon with the Blood affinity and the Bloody Slash ... You can start from the Fort Haight West Site of Grace, and from there, go downhill and turn around to find ...

then unleash a flurry of thrusts that rob the target of both their blood and their HP. Once here, to get the Ash of War, you must first find the Palace Approach Ledge-Road Site of Grace ...