Courage had nothing to do with strength.
The rage of a commoner could cause blood to flow five
Ling Han charged back with Cheng Tao and Fu Yuan, destroying seven of the Dark Frost Celestial King's camps in just half a month. Only then were they willing to stop for a rest.
Cheng Tao and Fu Yuan naturally did most of the hard work. They were afraid that Ling Han would be dissatisfied with them and suspect that they were still loyal to the Dark Frost Celestial King.
Ling Han temporarily stopped his advance. This was because they had already occupied more than nine camps. Occupying any more than this would be useless. Moreover, if they continued to advance, they would get closer and closer to the Dark Frost Celestial King.