"During that era, there existed only one method to strengthen and temper one's body, and it involved a process from the inside out.
The individuals of that time adhered to this process of body tempering as their primary means of growth.
At the outset, an individual would focus on sensing the flow of mana within their body. Once they developed the ability to perceive the presence of mana within, they would commence utilizing that mana to forge intricate mana circuits within their bones.
Mana-circuits refers to a path through which mana flows. They play a fundamental role in controlling the flow of mana and enabling magicians to guide their mana in a unique way.
The mana-circuits would be intricately formed, radiating outward from the central core of his being, originating from the backbone and extending throughout his entire physique.
It was a painful process, as creating mana-circuits inside yourself required a lot of control and precision.