Soul Devouring Formation was a very evil formation, it was also called Spirit Transfer Formation. Even a level one Soul Devouring Formation was very hard to set up as the materials needed weren't something ordinary people could acquire.
The main ingredient needed was Soul Devouring Wood, it grew in very hidden places without any sunlight. If it was exposed to light, it must be picked away immediately or it would wither.
The reason Soul Devouring Formation was evil was because it could transfer a cultivator's spirit roots. Through this, it could transfer a talented cultivator's spirit roots to yourself, making yourself better.
