In the earliest days, the spiritual control technique had all sorts of interesting uses.
Those talented spirit controllers acted as if they had obtained an interesting toy and kept on inventing new variations of spiritual control techniques.
Summoning a bunch of ghosts and creating a haunted house!
Having exchanges with death bone and soul remnants!
Seizing the souls of small animals and turning them into puppets!
...
Back then, many strange spiritual control techniques appeared. Out of which, some were later listed as forbidden techniques.
Any living creatures, humans included, craved power.
It was because power represented food, a filled stomach, and a higher cultivation realm. It thus represented dominance and even freedom.
