In a way, Harloys' teaching style was indeed incredibly effective. Not only were her soul books capable of directly injecting knowledge, even the practical combat experience could be gained as well. This was absolutely cheat-like in its power.
But on the other hand, this learning style was far too dangerous.
Every individual would have their own characteristics. Apart from obvious physical characteristics, more important would be one's internal characteristics. The so-called internal characteristics could only be one's memories and soul, while a personality would be the product of one's memories and soul. But, since it was possible to transfer memories in this world, it would also be possible to transfer personalities… Besides, Harloys even gave me a concrete answer. She confirmed that she had indeed mass-produced identical clones of a low-level mage before.