My Evil Genius Wife - Chapter 516 - Wedding VI

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.

Despite being the ruler of a nation, nobody was willing to marry the vicious man with a bloodlust.

The free-spirited and brutally honest Ye Zhen Zhen was unwillingly chosen as Empress to the playboy Emperor Ji Wu Jiu. Their very first wedding night, she kicked the Emperor down from their bed and he sought out his concubine instead. This completely disastrous start was only the beginning of their eventful life together.

Protagonist travels between different anime worlds to right wrongs and uncover his reason for being along the way.

- Description from Novelupdates