What do I mean when I say "eat the knife twice"?

I am used to watching many tragic cartoons.

There are many anime endings that are not so beautiful, such as the magical girl Xiao Yuan; Rebellious story games, underground slaughter line and peace line, secondary creation under depravity and fear, etc.

Many malicious authors will make some secondary works based on the original works, which will make people who know and love the original feel sad and painful for the characters in the works after reading them, just like someone has inserted a knife in his heart after reading them. However, these works sometimes have a charm that people can't stop, just like knowing that there is a tragedy ahead, but there is a desire to continue reading. This is called eating a knife.

I want to recommend the knife I ate recently. Under Fan Hua, I suggest that we first learn about the original "The Slaughter and the Peace Line" by undertale, and then look at Fan Hua's works under "Fallen" on the basis of limited depravity. Under the depravity, it is the reversal of undertale.