A special bone collected by members of the covenant of Mound-makers, discovered in the corpses of their victims.
Only one such bone is found in the vertebrae, and the Mound-makers believe it to be a shackle of the gods. In their minds, each victim is another connection, an addition to the family.
- Dropped by Mad Spirit Holy Knight Hodrick in Undead Settlement. He will invade the player near the Dilapidated Bridge bonfire.
- Dropped by Skeleton Swordsmen.
- Invading or getting summoned by another player as a "mad" spirit (purple sign) and killing either the host or any summoned/invading phantom. Note that as a mad spirit you can damage anyone and anyone can damage you.
Acquiring them offline is possible at a medium rate (~8/hr) by fighting the two skeletons just before the Catacombs of Carthus bonfire. Short video guide (melee): https://youtu.be/1qIP6HuCwaI