The mc is basically the reincarnation of the guy who tricked the snake and killed it. So the snake refused to cross over to the other side and is seeking for revenge. Ig it has been happening for 9 times considering the 9 skeletons.
The old monk might be the snake's trick to release him from his shackles(no idea why his heart has shackles in the first place. Might be the price he has to pay for refusing to cross over or might be his way of preserving the body¿ no idea)
Also the snake use the same reason why the guy killed him in the first timeline which is wealth. And he's been using the same trick all across 9 reincarnation. It answer his "you've been fooled again" statement.
Well this is what understand. The storyline have potential, too bad it's just a short story










The war is endinggg. Can't wait for season 3!! I love you author for writing this peak!!!