I’ll Quit Being a God - Chapter 517: Paths of Their Own

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.

Her first encounter with Qin Sijue is an unexpected one. While trying to hide from her pursuers, she accidentally barges into his changing room. Yet, their paths crosses again fatefully—after a fake marriage, she legally becomes his bride. She imagines that they will only interact before the agreement ends, after which they would have nothing to do with each other. However, Qin Sijue comes over with two red booklets—their wedding certificate. “Take them for an appraisal and see if they’re real”.

A young man who had longed for stories of good and evil since childhood lost his life in a tragic accident and was reincarnated as a boy named Chrono Mak in another world.

He learned that in this other world, there is magic and witchcraft, and depending on how you train them, you can become as strong as you want to be, so he decided to become the strongest demon king in order to recreate the story of justice and evil he once dreamed of.

The summer I was 17. A painting I created was sold. For 1.4 billion won.