All Realms Unite the World

The economy of the Song Dynasty was prosperous, the culture of the Tang Dynasty was strong, and the cavalry of the Qin Dynasty were countless... Sorry, they are all scum under the power of my mechanized troops. What, you said Europe has already experienced the industrial revolution? If an atomic bomb is dropped, it won't kill you. You said there are other worlds... It's okay, I have a super summoning system! My goal is to unify the world! Ah, no, it's about unifying all realms! This novel and its characters are purely fictitious. Any similarity is purely coincidental and should not be imitated.