After finishing Dan, continue to practice. This Dan will continue to move up along the midvein and gradually move to the top of the head, which is called three flowers gathering. At this time, the essence and qi are integrated, and the Yuan God changes from Yin God to Yang God, not afraid of the sun. At this time, Yang Shen is still very fragile. You need to constantly collect the free energy from the outside world and constantly condense Yang Shen to make it stronger and stronger. When you practice "dispersing into gas and gathering into shape", Yang Shen can travel.