Demon Lord Gets Married - Chapter 288

He is high above, the mysterious and terrible King of the Wild. With one glance, he can see people’s romances. He hates women to the extreme, but at his first glance of her, he dotes on her and spoils her.
She is a humble transmigrator, a miracle doctor who doesn’t care for the many handsome men around her. She only wants to become strong, to be worthy of that god-like man. But when she’s finally sure of her feelings, she finds out she’s already been married for years…
……
When wronged：
She uses strength to hit the big handsome iceberg-like man in front of her eyes. “People say that I’m not good enough for you, but it is you who is an old cow eating tender grass!”
A man seizes the main point and laughs like an evildoer. “This husband has to eat the grass to confirm if it is tender or not!” He puts out the red candle……
……
The world says：
The barbarian king has no heart and has no passion.
A pregnant woman very miserably thinks,” If he has no passion, then who is responsible for this big belly?”

- Description from Novelupdates

Reborn in a parallel world, this place is imbued with eeriness everywhere... Do not enter the bathroom after midnight. At two in the morning, the sound of knocking resonates on time. A woman, haggard and emaciated, always stands with her back to oneself. Encountered a strange event? Lucky for me, I can Rewind! This is the story of a Reincarnator, carefully navigating a reality invaded by the bizarre, combating the strange with bizarre poses.

Lu Chang’an cultivated the reincarnation of immortals for two generations, and in the third life, An Wengou reached the Nascent Soul stage, solved the mystery of the reincarnation stele, and then practiced the mediocre ancient health-preserving skills.

Avoid fighting and fighting, operate steadily, and form good relationships with people.

After a long cultivation career, I got acquainted with growing characters, upright leaders, celestial beauties, demon giants, evil cultivators, thousand-year-old monsters, behind-the-scenes chess players…

Watch the ups and downs of the world, the ebb and flow of the tide.

Unknowingly, it has become a living fossil in the world of cultivating immortals, an evergreen tree through the ages.

…………

Mortal flow, stable, pseudo-longevity, decisive killing, and normal three views.

- Description from novelbuddy

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.