MTL - This Star is a Bit All-around - Chapter 318 Big Yanyan in the future (subscription required)

Zhuo Yifan was the Demon Emperor. One day, he managed to lay his hands on an ancient emperor’s book, the Nine Serenities Secret Records. As the book was coveted by many, he was targeted by experts and was even betrayed by his student.

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.

The happiest thing in the world is to be able to amend what you have done wrong. She who acted willfully because of a game, was reincarnated into a time when she still had her parents’ love.

Transcend to become the prince of Daxia, activate the Devil Emperor Summoning System, summon the powerhouses from other worlds, and fight for hegemony in the heavens!

If I were the Devil Emperor in the future, I would definitely let your blood stain the sky!

- Description from novelbuddy