Saving the Heartthrob Frenemy - Chapter 23: "The class president smells really nice,"

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 end of all worlds approaches.

The Demon King Order harvests lives from all manners of living beings.

Within this darkness full of despair,
A single person escaped from space-time, returned to before the world collapsed, determined to change the fate of the past.

But as time pass, he gradually finds out that the Apocalypse isn’t quite as simple as he thinks…

The iron widow, the spider widow, male hunter, the witch of Neuwanstein castle, the embarrassment of noble ladies…….

In the beginning, I just wanted to solve life problems.

Then, I didn’t want to admit defeat, I didn’t want to just leave in such a daze.

Next, now that you’ve stood your ground, why not do it better.

Finally, as I have always insisted, when you decide to invest in something, you must do it to the best of your ability!

– One of the greatest actors of the 21st century, Sean Tang

- Description from novelbuddy