My Empire Reborn in Another World

In the jungle, a mercenary instructor who was tired of war was unexpectedly reborn in another world and became the son-in-law of the royal family. In order to protect himself in the struggle of the wealthy family, he once again embarked on the road of conquest. Since then, he has planted industrial civilization, opened the magic box of science and technology, occupied a county, competed with the world's heroes, competed with emperors, and enslaved cultivators at his feet. Let your cultivators go to heaven and earth, and your methods are unpredictable. I have the sword of science and technology to cut you down to the mortal world.