The Spirit Lock Circlet was a confinement spirit tool that—once activated—would lock the True Spirit to forever confine the soul.
Many large cultivation clans would use such methods to control their servants. Most of the servants of these clans were cultivators as well, and not only were they in Foundation Stage, but some were even in the Golden Core or Budding Soul Stages as well. These types of people were extremely dangerous, and given how much power they had and how vast the land was, why would they willingly choose to become a flunkey to someone else? Someone had created this kind of spirit tool specifically for the sake of locking the spirit and soul of a cultivator to prevent betrayal. Once someone gave an oath, the circlet would lock the cultivator's soul and prevent them from violating it.
