So my theory:
Yun Che = Power and Will of Evil God
XQ = soul fragment of Heaven Smiting Devil Empress (Evil God’s wife) sent when she first opened the wall a bit. Basically a scout to understand what is happening now.
Xia Yuanba = reincarnation of Mo E
Shui Meyin = Reincarnation of Li Suo
Luo Changsheng = Reincarnation of Xi Ke
Xiao Lingxi = Soul Fragment of Ancestral God
Basically they living people with special bodies as well as Xiao Lingxi are reincarnations but without memories.
If that is the case, I suspect that XQ got some of her memories back when she hit Divine Master level. Not everything but some.
One of the possible outcomes and the one that XQ has seen and YC is dreaming about is that the Devil Empress decides to roll back time and not come back. This creates the cascade where YC dies before the wedding but doesn’t reincarnate the first time and all the follow on stuff doesn’t happen. More dreams might show what happens to his BPS wives and Jasmine dying.
From this, my guess is that YC will work very hard to prevent that outcome as he doesn’t want to lose everything he had.