What kind of monster was he fighting? What era is this science fiction novel set in?

An old man picked up trash together. Because he couldn't afford an armor, he picked up trash and made a trash armor. They found a "good thing" in a ruin (I don't remember what it was exactly, but there was a potion that allowed the protagonist to devour monsters and become stronger). Later, a group of regular soldiers came. It seemed that the old man died here, and the protagonist drank the potion. After that, he couldn't remember anything. Did anyone know? Ask for the title of the book. (The above content may not be completely correct. It might be the case if the similarity is high.)
Right, the protagonist also encountered a Doomsday Moth that specialized in eating metal on a certain planet. According to the above, it was the Doomsday Moth mentioned in the Bible.

Answer 1

I recommend the book "Zombie Attack" to you. It is a modern science fiction novel. It is based on the story of humans being infected by a biochemical virus and causing social unrest. It describes the story of the protagonist,"Wang Jiaju", and his companions escaping from the outside world. In the story, the protagonist grew by devouring mutated creatures. This book is set in the era of the universe, you won't be disappointed! I hope you like this fairy's recommendation. Muah ~😗