This is not really a back door.
If anything, it's an additional feature that helps cultivators discern their physical condition, heal internal injuries, and gain a better understanding of their own bodies.
If one is unaware of their specific situation, or the specific situation of their student, even the best teachers would be at a loss on how to proceed, and any discussion of one's own progress and improvement would be out of the question.
If it were someone else, they would be overjoyed at this moment, eagerly swallowing the elixir and directly refining it—Chairman Chen certainly wouldn't mind having a protector, the guidance of a True Person at the peak of Purple Mansion, assist with healing hidden injuries and dispelling Demonic Qi, which would undeniably be of tremendous help.
But An Jing is different: he truly has something formidable to hide and cannot afford to have his strength completely exposed.
