Time Travel at the Same Time: All Amnesiacs

People in a different world, my aunt's world, travel across all heavens and realms at the same time. Good news, time travel at the same time. Bad news, natural abilities cannot be integrated. Good news, I'm the only one who knows the plot. Bad news, everyone has amnesia. Every other month, Hao Yun can possess the amnesiac boy and enter his world, and when he returns, he can acquire one of his own abilities. Ps: This book is also known as "Simultaneous Travel: Saving the Doomsday of All Worlds", "Simultaneous Travel: You Can Die, But You Can't Live", "Simultaneous Travel: All Difficulties in the Underworld"