In the novel Tomb of the Gods, why did Chen Nan, who died for ten thousand years, come back from the ghost graveyard? What happened ten thousand years ago?

Chen Nan's Resurrection is a game laid out thousands of years ago, and it is one of the most important chess pieces used to destroy heaven ~ ~ ~ Chen Nan is the tomb of the gods, bearing the power of all beings. He has the residual souls of all the gods in the ghost cemetery, which is also the purpose of Chen Nan's resurrection. Destroying heaven requires the power of all living things. There is a coffin in the ghost map, which is needed for the combination of residual souls, possibly to make Chen Nan's soul fit in the future, although the author didn't say it. However, we can clearly see that Chen Nan is actually a lonely and small failure. As for 10 thousand years ago, nothing happened at all, but once again all beings were wiped out by heaven, and countless ghosts and gods perished, forming Oni Tsuka ~ ~ ~