In the Soul Refining Demon Cave, to survive, one must exist in the form of a Yin Spirit to have hope.
Otherwise, no matter how strong you are, entering the Soul Refining Demon Cave, the survival rate is essentially zero.
The condition to advance by killing three Tai Chu Yin Spirits is not to bring cultivators to the Soul Refining Demon Cave to die, after all, places with Yin Spirits are not limited to just the Soul Refining Demon Cave.
It's just that the Soul Refining Demon Cave definitely has Yin Spirits, whereas other places may not necessarily encounter Tai Chu Yin Spirits.
The difficulty of this ascension task for the Purgatory Refiner is truly meant to make the aspirants either retreat or use their wisdom and skills to complete this nearly impossible task.
This is a true test of life and death.
