Although Zhao Yun is strong, in circumstances where he wants to capture the opponent alive, the Celestial God mode either outputs too much power or too little, making it difficult for Zhao Yun to get it just right.
Of course, a crucial point here is that Zhao Yun truly didn't regard the opponent as a Breakthrough Level expert.
In Zhao Yun's view, the two guys opposite him couldn't even control their power. Although strong, relying on Breakthrough Level qualities to beat most Ultimate Inner Qi Manifestation in the Central Plains was no problem, but when facing experts from the Central Plains with nearly equivalent hard qualities, the danger was not even as severe as with Pang De or Zhang He, the Ultimate Masters of Inner Qi Manifestation.
