Original mod link: https://modworkshop.net/mod/20436#description

I only edited it to change when you restart the game.

When the game starts, it chooses a set of difficulties from Classic Doom or Doom 64 or Zandronum/Skulltag and applies it to the game (changes when restarted, duh) along with changing the description of difficulties

There's 2 files, the normal file which chooses the entire set from 1 game or the Random file which chooses randomly from all games and also randomises descriptions of difficulties. Choose only 1 out of the 2 files