I’ll Quit as The Empress - Chapter 88: Love At One Time.

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.

She, the top goddess in the showbiz, officially announced her marriage, with her husband's identity remaining a mystery.One day, a news story went viral claiming that she was seen entering a villa with a strange man in the midnight and didn't leave until morning.Someone recognized the man as a financial tycoon, who is mysterious and low-key, and no one dares to offend him.That day, she clarified the rumors during a live broadcast, “It's all rumors. Please don't misunderstand. We are just friends.”Just then, he himself stepped up and said, “That's right. We're just friends for now.”...Everyone knew that their marriage was just a commercial arrangement devoid of any real emotion; otherwise, he wouldn't have left his wife to go abroad for two years right after their wedding.Just when everyone was waiting for their divorce, a secretly shot video suddenly went viral online.In the courtyard, the man who was always casual, proud, and superior, knelt on one knee in a pious posture, massaging the woman's ankle. His low and sexy voice captivated everyone watching the video as he said, “Sweetie, would you like to remarry me?”Damn! It's so sweet!

One day, Zhang Chenfei met a car accident. Fortunately, he didn’t suffer any serious physical injuries. However, due to the impact of the car crash, his brain’s perception of the real world had turned into that of the novel that he was reading prior to the accident. The thing that horrified his wife, Jiao Qi, was… the Smart Brain, Louis XIII downloaded a series of books which meant that his husband would turn into a different character each time!

How will our adorable little wife deal with this kind of husband who seemed to suddenly suffer from multiple personalities?

This novel’s plot focuses on Zhang Chenfei’s changing personality based from the characters in the books, and how his wife, Jiao Qi, deal with every character as he will have to act in sync with whoever his husband’s character is. This is per the advise of the private doctor since treatment of this special condition was still under research.

As they act out their roles, they will gradually discover and learn more about the other, which they’ve never known in their seven years of living together.

- Description from Novelupdates