Raziel would take the spear to the Water Forge room where he would use it to imaple one of the stone Hylden statues seen above the water forge warp. This cracked the murals featuring the same spear and enabled Raziel to access further into the Mansion. When all three spear were collected and used to impale the Hylden statues, a warp to the Water Forge was created.
The Blood Drinker spear represented the vampire aspect of Raziel.
Several murals in Vorador's Mansion depict the spear in use - presumably showing scenes from the Ancient War, the spears are used as weapons to impale several Hylden enemies. Copying these actions on the stone Hylden statues in the water forge room enabled Raziel to solve the puzzle of the water forge room and enter the water forge.
The Blood Drinker as it initially appears in Defiance