The Eye of the Beast King had the ability to control hundreds of beasts. Zhao Hai did not think much of this ability at first because he did not want to control all of them. If he really needed to control any beast, he could just keep it in the origin space and the Beast would naturally be loyal to him. He was more assured of using it than the Eye of the Beast King.
As for the other eye techniques, Zhao Hai did not pay much attention to them. Although he knew many eye techniques, the Eye of the Beast King was a pair. Using one eye technique alone would not be very useful. Thus, even though Zhao Hai had refined the Eye of the Beast King and kept it in his body, he had never used it. He had almost forgotten about the existence of the Eye of the Beast King.