Chains Of Entrapment

Description
Chains Of Entrapment, Specialty Item These great, dark, steel chains were made specifically for the purposes of binding one specific being to a set place, The Viridian Betrayer. The creator of these chains, the Thrall King, made the earthen prison for Favoris as a punishment for her past crimes. These chains cannot be broken by anyone other than the Thrall King, who has long since passed on to the afterlife. These chains are created, empowered, and fueled by the breath of  Dragons. These chains cannot be pulled out of the earth; if someone like Favoris tries to dig the prisoner free, then the chains will automatically  create  new links to keep it anchored to the ground. Attempts made to break these chains are punishable by death, and punishment is to be delivered by the Thrall King.

Reference
Chapter 112 "The Monster Of The Burning Pass." (Cliffe)