He can't control everything completely.
Most importantly, whether one can overcome the Heart Demon depends on the level of the one undergoing the Tribulation Transcendence.
Even the lowest threshold of Supreme Unity has its limits.
Luo Hou could nominate the Devil Bull King, but whether he can clear the level depends on whether the Devil Bull King can win on his own.
The National Soccer Team can play in continental and international matches by paying, and it won't prevent them from making a fool of themselves before the whole world.
The situation with the Devil Bull King is the same.
Luo Hou is at most like the "National Team's coach" who has been paid, he has already sent the Devil Bull King onto the field, but whether he can win, he can't control.
But Ji Changsheng didn't care about that much.
