Saving the World Starts with Making Armor

PS: This book is slightly dark, realistic, and a unit drama. It does not focus on shaping the protagonist. The protagonist is absolutely invincible. If you don't like the above, don't read it, and if you don't like it, don't criticize it! Wear a parallel world and get the system. I thought I could live a prosperous life as a boxing king. As a result, the system told him that the world would be invaded and destroyed by the Shadow Realm in one year. Ever since, in order to survive, a company named Zaiya resolutely appeared in everyone's field of vision.