Apocalyptic Martial Arts Game

When the end of the world came, great changes occurred again. The end of the world was integrated with a game called "Martial Arts", making the world gamified. The imaginary game world becomes real. The real world is like hell. The earth is full of space cracks, which are the entrances to the game world. The survivors of the apocalypse go to the game world to obtain adventures and skills. (There are martial arts stories you are familiar with.) And the NPCs in the game world will eventually come to earth. In addition, there are powerful monsters that have received broken marks and martial arts inheritance. The crazy lion overlord who knows how to roar, the monkey king who uses flying knife skills, the undead zombie who practices the golden bell and iron cloth shirt...