Reincarnated as a Failed Villain: Fallen Angel - Chapter 60 Arc 2 - Still Need A Catalyst

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.

He transmigrated and got a system but Lin Feng’s pressure is as big as a mountain.

Ye Hai traveled to the Marvel Universe, with a large scientist system, and IQ completely exploded all Marvel superheroes and rebels.

     “What is Iron Man? His steel suit is all my cottage! Tony, I seriously warn you that you have to pay me patent tax!”

     “The Hulk’s stuff is harassing me again, isn’t it just turning your ass red? But I have solved your problem of getting out of control, and a little sequelae should be.

     “Captain America, don’t always show off your shield, your shield is not unusual, I can mass-produce it!”

- Description from b faloo