The Goddess, Please Devour the Evil Deity! - Chapter 7Vol 1. : Familiar Breath and Gradually Evoked Memories

A calculating merchant of noble birth lives a comfortable life managing his guild's business at the Imperial Academy—until lightning strikes him, leaving him with prophetic visions of a disastrous future. In these visions, he's expelled from his family, branded a traitor who aids demons, and worst of all, becomes a penniless beggar. When the supposed “protagonist” of these prophecies enrolls at the academy, he realizes his countdown to ruin has begun. Now he must use his foresight to rewrite a story where he's cast as a third-rate villain, all while navigating ancient dungeons, demonic threats, and the troublesome “hero” who might be the key to changing his fate.#MoneyIsEverything

Mimizuku, a small girl with chains on her wrists and ankles and the numbers “332” branded onto her forehead, wanders into the Forest of Night seeking to be eaten by a monster. However, when the ruler of the monsters, the mysterious and beautiful “King of Night,” refuses to eat her, she tries to formulate a way to convince him otherwise.

A scientific genius named Thomas Harrier was transmigrated to an imperial prince body after a car accident that took his life. He found out that he is in a world similar to our own with a timeline akin to early twentieth century. The body that he is occupying was the imperial prince of a failing empire who suddenly rose to power after a successful assassination attempt of his father. Unaware that the attack is just the beginning of what is to come. He faces many challenges throughout. Will Thomas Harrier be able to live his second life in peace while running an empire and getting it back to its former glory? Or will he succumb into a conspiracy lurking within the country's borders?

Expect some:

Cold war era techs.

Super battleship with advanced electronics, propulsion, and fire control systems?
Helicopters?
Missiles?
Modern medicines and equipment?
AC-130?
A nuke?
Challenger or Abrams or Leopard?
F-4 Phantom or MIG-21?
Colored TV's.

Everything!!!

PS. Cover not mine, I just found it on google.