My Classmate is 200 Million Years Old - Chapter 177

The fool of the Old Mu Family, Mu Shuangshuang, who was bullied by everyone, suddenly changed one day! She was not foolish anymore, and she knew how to fight back when bullied. The dirt thrown on her was returned little by little. The once famous fool of a woman suddenly became smart, became beautiful, became wealthy, and even had an admirable good husband by her side, living a leisurely and carefree life from then on!【New book 'Rebirth Blessed Wife with Space' has been released, old book 'Rebirth Farm Girl is Stunning'】

Seol Woon-hwi, the Blood Heaven’s Righteous Blade, rose to power, becoming second to none under the heavens, reigning just beneath the sky itself.Yet, at the height of absolute power, he finds himself returned to his past—back to his days as the scorned illegitimate child of the Everlasting Snow Palace.

The Nightmare BeginsDr. Emma Taylor, a renowned psychologist, had always been fascinated by the human mind's darkest corners. Her latest patient, a young woman named Sarah, suffered from terrifying nightmares that seemed all too real.

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.