Crazy Demons and Delusions

If one day you fall into an impeccably real world of illusion and immortality, but the so-called reality gradually loses touch with your memory, and everything is misplaced and contradictory, at that time, can you still tell what is reality and what is illusion? Or maybe the reality we have always believed in is a lie; and the so-called illusion is the real world. Ye Wuxie was crazy, but not completely crazy. It might be twisted.