Moonscars

The point of this achievement is to locate the talking head to the left of the Throne Room mirror in High Castle. You will notice he is missing his limbs and the game suggests finding and reattaching them. Once you have all four limbs, return to the Throne Room and reattach the limbs. The talking head becomes King Drahan. Feed him bone dust and he will tell you the story of how his kingdom fell, and he was cut into pieces. You will need to do this 3 times, costing a total of 30,000 bone dust. Once you've exhausted his dialogue, the achievement will pop.

The left arm is located in High Castle, two floors above The Memorial mirror, at the left end of that hallway. The left leg is in the upper left room in the Mould Workshop, which can only be accessed after obtaining the ability to open flesh wall barriers (defeat Royal Infant for this). The right arm and right leg are both found in The Depths, and I believe you will need the Corpse Pits key to reach both limbs there. The right leg is closest to the Corpse Pits mirror. You will need to climb all the way to the top and go east when you can't go any higher. You will find it near the gate that unlocks the path to High Castle (nearest High Castle mirror being The Nursery). The right arm is found by descending from the Lesser Mills mirror. There is a long, two-floored section you can access south-east of the Lesser Mills mirror (check map, the description hopefully makes sense when looking at the map). The limb is on the west end, upper floor of that section.

Apologies for any confusion with my descriptions. It is kinda difficult describing the locations of some of the limbs. I found this guide with pictures showing limb locations - https://video-game-guide-walkthrough.supersoluce.com/solutio...,%28pictures3and4%29.%20%E2%80%93%20Right%20Leg%20in%20the%20Depths%20%28pictures5and6%29.

Hope this helps anyone needing it.