To become an Alchemy Sage, one must possess a Sage-level Alchemy Stone.
The prerequisite for possessing a Sage-level Alchemy Stone is to sign a soul contract with the head Sage of the Alchemy Cathedral, never step out of the Golden Federation, and never reveal the core secrets of the Cathedral. Only after completing this step can one use the Soul Transposition Array to upgrade an ordinary Alchemy Stone to a Sage-level Alchemy Stone.
This condition can be described as extremely stringent and even perverse.
"Our neighbors in the far corners of the world basically have their own set of rules, Jarvis. The Alchemy Cathedral is like that, and so is the Tatis Empire. Due to the lack of historical records, I can't help but wonder if they are extraterrestrial void forces that arrived in this world from outer space.
"Apologies, I digressed.