Bestow Whole Favour on My Lovely Wife - Chapter 13 - Tian Mi, you wait

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.

Darkness is coming, and crisis is everywhere. In this long dark and desperate night, do you want to see a bonfire with warm words? We are that light.

We don’t want to be the little bully who guards one-third of an acre and eats canned food.

We don’t want to drive the harem on a great escape from east to west.

We don’t want to be a bunch of rats guarding rancid cheese in the gutter.

We don’t want to see the panic on your faces and the desperation in your screams.

So we stand up, fight for ourselves, fight for you, fight for humanity!

As long as we are here, the flames of war will never be extinguished.

We light a warm bonfire in the dark night, and watch the dawn with the brilliance of life.

We are the shield of the earth, the patron saint of mankind!

- Description from novelbuddy

Lin An woke up and found himself in an Eastern Fantasy world.

She was a famous plastic surgeon in the 21st century, both at home and abroad. But one day, she transmigrated to become a young lady in the Prime Minister’s Mansion and got bullied. The concubine hung her up and beat her, forcing her to marry a fifty years old general as his second wife! But unexpectedly, she received an imperial edict and was asked to marry the emperor’s fifth son – the Evil King.

Who was the Evil King? A gunpowder explosion destroyed his appearance and one of his eyes. After waking up, Evil King’s temperament changed drastically. The handsome young man became a bloodthirsty and cruel tyrannical king. This was not even the most frightening thing. It was said that the Evil King had four wives, but none of them had lived over a month!

Last night, the Evil King’s fourth wife died. Today, she was tied up and sent to his mansion …

- Description from Novelupdates