Nine Star Hegemon Body Art (WN) - Chapter 3268: Underworld Ghost Seed

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.

Choosing a college when your family is struggling can be difficult, but it isn’t supposed to be world ending. And the falling meteor is seriously limiting Matt’s options. Now in the aftermath, his home city is locked down by a mysterious dome, corporations are looking to monopolize a wealth of new untapped resources, and people are suddenly developing powers via a system that seems to have borderline sinister intentions. In the chaos, he decides to stick to what he knows: stay out of the spotlight, grind, and survive.Watch as Matt is dragged into a dark LITRPG set in the real world, where the price of failure is death, and the prize for winning is beyond his wildest dreams.

I became a scientist for an evil organization.…But I’m too competent.

He always told me that he dreamed of me at night.