This quest is not acquired from any specific individual. Instead, you must obtain four Blue Skull Effigies from the Necropolis located within the Blue Chamber in Berg.
Note: You must have completed the third faction quest for either The Heroic Kingdom of Levant or The Holy Mission of Elatt before you can access the appropriate area within the Necropolis. For The Blue Chamber Collective faction, you will enter the Necropolis during the third faction quest, Whispering Bones.
Once you’re inside the Necropolis, go down the stairs and turn east, then south down another set of stairs. This leads you to the depths of the Necropolis, where you will see a blue magical barrier blocking the entrance further below. To unlock the barrier, turn left eastward, and then right southward. A room on your left contains the first Blue Skull Effigy. Before you take it, loot the Greasy Ferns located in the corner of the room to the south east. You can now take the skull, but be ready to fight a ghost once you have done so.
Now head down the hallway to the south and turn left into another room with a Blue Skull Effigy in it. Looting this skull spawns a red ghost which hits much harder than a purple or blue one. Use the hallways to kite the ghost if necessary, to avoid any hits that might knock you down. When the ghost is dead, head further south to the end of the hallway. Here you will find the Sutherland Family Altar. Use a Greasy Fern to ease the spirits by interacting with the altar.
Once done, head north back up the hallway to where you found the magic barrier. Now take the western route and enter the rooms on the right side which contain Blue Skull Effigies. Taking each skull will spawn the same ghosts; one purple and one red. When you have all four skulls, head west into the room containing the Aberdeen Family Altar. Interact with it and place a Greasy Fern to unlock the magic barrier. You can now go back to the barrier and make your way down the stairs to the south.
At the bottom of the stairs, continue south down another two sets of stairs. At the end of the hall turn east. You will find Cremeuh in this last room. Speak with him and provide him with the skulls to complete the quest.
Note: As reward for completing the quest, Cremeuh crafts you an Ornate Bone Shield from the skulls. The shield inflicts 19.2 physical damage and 12.8 Ethereal damage on contact. In addition, it inflicts 51 impact and provides 17 impact resistance.