Do You Call This an Engineer When It Comes to Hand-Rubbing Electromagnetic Guns in the Apocalypse?

Introduction [The end of the world is coming, monsters are rampant, and human civilization is in danger. When others awakened their powers and fought hand to hand in the beast tide, Shen Yuan just silently picked up the rusty wrench. The "useless knowledge" he was ridiculed for was the last fire in this world. "Look, that engineer is tinkering with his shit again." They didn't know that Shen Yuan's electromagnetic gun could pierce the head of an S-class beast king with one blow; the shelter he transformed was the only kingdom of God in the apocalypse; and the mobile steel city he built became a monument to the survival of human civilization. When the destructive-level "Mother's Nest" awakens from the center of the earth, all awakeners are in despair. Shen Yuan pushed up his glasses and pressed the last button. "Don't use your brutality to challenge my carefully designed... Physical laws."