Brion could easily use his mind power to control both Tarkos and Givan easily because of the power difference between them and himself, but he did not do it.
He used his creation to control them if needed.
There were about three reasons why he did not use his mind power directly.
The first reason was unknown abilities of the magical world, Brion did not know if there is somebody who could recognize his mind power after checking the Tarkos and Givan
The second reason was consumption of the Mind Power, as he always said that using mind power in the purest form for his abilities and purposes cost him more energy than usual.
The third reason was he was testing his abilities and trying to improve other things, which was worked for him.
After he planted the small robotic controllers that he made from his mind power, a system message manifested in front of his eyes.
"New Study"
"Robotics (Level 1"