Sage Monarch - Chapter 1515: Subjugating the Sword Lord

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.

There is luster in the east, and it is named Dahuang. “
In the rumors, ignorance, poverty, backwardness, and wildness. “
– bullshit. “
Queen of the Great Desolation, cold as frost. “
Supported by the national teacher, and the golden boy and jade girl of the national teacher, they are deeply in love, a stunning couple, and unparalleled. “
– bullshit. “
The queen died suddenly, and the national teacher mourned. According to the instructions of heaven, they traveled thousands of miles and finally found their reincarnated lover. From then on, the prince and princess lived happily in the castle…
——Crap! “

- Description from novelbuddy

The mid-level boss of my company’s AAA-game.

Ji Yan discovered his wife, who hated him so much that she wished he was dead, had lost her memory after a car crash. She had changed so much it was like she was a totally different person…

When he goes to work: “Dear, don’t move, I’ll put on your shoes for you.”

When he is having a meal: “Dear, I have made all of your favourite dishes. You have worked hard, so eat up.”

When he finished work: “Dear, you have worked all day. I’ll massage your shoulders and feet.”

Ji Yan: “…”

—————-

Tang Tang got pushed into the pond by her step sister who frequently bullied her. She thought she would meet her dead mother but, who knew, when she opened her eyes again, she was in a strange place. But what made her happy was that she had a super handsome husband and a very cute son. The most important thing was that her husband was good. He was a hero who protects the country, and earns money to support her and their son. Also, he only has her as his wife, he didn’t have any concubines or whatsoever. Tang Tang decided she should be submissive to her husband, to be a good wife and a loving mother. Her nanny no longer needed to worry about her not being able to get married anymore!

- Description from Novelupdates