There is a fork in the road in Bagong Mountain. Go to Luo Yan on the left and Huainan Tomb on the right.
The picture below shows how to get to Huainan Tomb.
There will be a plot trigger in Huainan Mausoleum. Take your time. Wanshan is basically not a maze. When you come out of Wanshan, you arrive in Chen Zhou.
If it's not your first time in Chen Zhou, I don't need to say anything about Royal Sword's flight.
But I think you should ask the first case.