After the group from Dragon Tiger Sect left, Happy continued to train in the valley. His Cloud Treading Steps might have reached the ninth realm, but he was still a distance away from being able to move to heights not possible by human means and anywhere else he wanted at ease.
If he reached Grandmaster Realm, he would need very little qi when he used his lightness skill, and the increase in his speed and the height he could reach would also far surpass what he could do at that moment.
His Complete Reality Qi Cultivation Technique had also reached Level 86. He was still thirteen levels away from Grandmaster Realm, but when he reached it, his qi cultivation technique would activate on its own. He was still a long way away from it, however.
