The current speed of training, naturally let him very dissatisfied.

Having a psionic crystal would speed things up a lot.

A psionic crystal, a collection of reiki into crystals.

It is possible to excavate "natural psychics" from underground veins, or to kill wild beasts and extract "acquired psychics" from their bodies.

One psicrystal was usually worth as much as a thousand silver coins, and only a great nobleman, or a genius raised by a great family, had access to it.

One thousand silver coins, to the present Zhang Ruochen and Lin Fei, is absolutely a huge number, it is impossible to afford.