what did cole suddenly realize about power, now that he had so little

I think you are referring to when the Spirit Bear mauls Cole. Cole feels all his manipulations, anger, fear, and attitude stripped away from him. He is completely emotionally and physically vulnerable to nature's indifference to him and the bear's whims. In many ways Cole begins to see that he had the illusion of power through manipulation. Cole cannot manipulate nature or the bear. He sees who he really is.