The formation of the Elixir is a process of fusion and transformation of the essence within the Immortal Herbs.
This Tao is, in fact, nearly identical to how a human body devours medicine to undergo transformation. It is precisely for this reason that the Alchemy Skill can bestow various insights to its practitioner.
Zhou Yan imparted the Alchemy Skill to Hou Chen, mainly to allow him, in his future cultivation, to settle down and advance more stably.
Compared to other cultivators who spent countless years reaching the Sword Void Realm, Hou Chen's cultivation time was very short, and his increase in combat power was particularly terrifying. Even if this rapid and powerful realm were to merge with Hou Chen's youthful and immature heart, there would still be some deficiencies in his character.
This is best exemplified by Hou Chen's act of urinating in the Evil King's Secret Realm Holy Land.