Breaking Out of the Siege, I Can Go Back Infinitely in the Treacherous Realm

I don't know when, the human world was infiltrated by strange things. They devoured the fire of human civilization and set off a wave of terror and despair. I don't know when, a young man walked silently alone in the strange ruins that looked like purgatory on earth. Only rules are the passport to survival, either obey them or create them. It is both a sharp spear and a strong shield. In order to survive, to find the missing girlfriend, for the slim hope... "For an illusory tomorrow."