To be precise, a Legendary Mage meets the minimum requirement to craft a Philosopher's Stone, but the success rate is very low, and success is almost impossible.
To obtain the Philosopher's Stone, the crafting material must be that of a Demigod.
A Demigod's Life Domain can influence others, granting knowledge and power, creating its own kin.
The holder of the Philosopher's Stone will gain the abilities of a Demigod, able to unfold a domain to create kindred, and due to the enhancement of Alchemy, the Philosopher's Stone has a wider applicability and its influence far surpasses that of a Demigod.
Saina cited a simple example, She is a follower of nature. If she has a Philosopher's Stone, she could imagine in her mind and create kindred of death and darkness.
This stone not only grants the user a Life Domain but also allows the user to fully harness their talents, projecting imagined things into reality.