Yeyu Lin himself had once tried to manufacture one. However, human-shaped soul tools required far too many core array sensors.
The demands on the material of the body, the connection of the core arrays, and the control by the human body itself were all extremely high.
Building a human-shaped soul tool that could be controlled by a human was not difficult. The hard part was creating a human-shaped soul tool that could drastically increase one's own strength.
Chapter 724