Just before she was about to break through, Ye Qingtang suddenly sealed up her spirit energy.
In the Second Domain during her previous life, Ye Qingtang obtained a special skill. This was the skill which enabled her to finally ascend to the Emperor level toward the end of her previous life.
This skill was called Spirit Sealing.
As the name suggested, this skill could temporarily seal one's spirit energy. As one's spirit energy increased with cultivation, the amount being stored would also increase. After reaching the maximum limit, the practitioner could then unleash all the spirit energy at once. This spirit energy would be more vigorous and trigger a breakthrough in the cultivation level.
This kind of skill might be good but it could only be used by practitioners at Paragon Fifth Heaven level and above. As long as the stored energy was enough, it could trigger a breakthrough when unleashed.
