The memories from Demon Shore were voluminous; Gu An's greatest aid was in understanding the Reincarnation Tribulation.
Reincarnation Tribulation indeed allowed one to be born into different spacetimes, even to the past, but whether it was the past or future, one's original power was unable to intervene. The Reincarnation Body would either be forced back by the Heavenly Dao when it died or when it exerted its original power.
This made Gu An think of Ji Xiaoyu, who had previously exerted the power of the Innate Dao Talisman within the Seven-Star Spirit Realm and then vanished swiftly; it seemed she was expelled by the Reincarnation Tribulation.
This gave Gu An a deeper understanding of the Heavenly Dao.
The Heavenly Dao seemed more like a collection of rules and the Great Dao, intricate and dominant.