One of the requirements for the Heaven's Primal is a rebirth of one's body and the understanding of techniques as well as a body protection aura.
The Heaven's Primal is a boundary for cultivators. From this level onward, the further progress is no longer depends on one's aptitude and talents only, but it also depends on one's Merit Laws, Treasures, etc.
Once a cultivator reached the Heaven's Primal realm, they could refine their True Fate into a Heaven's Will Primal Soul, allowing their True Fate to escape from their bodies. This way, even if their bodies get destroyed, they could still build a new one.[?]
Once reaching the Heaven's Primal realm, cultivators could fly without relying on any treasures.