Soul-swapping:Imperial concubine rebirth - Chapter 13

Nora is transported to another version of Earth populated mostly by men. A world where women ruled with absolute and unmerciful power. Nora must protect herself, her identity and the group of men that she is forced to love. Will she be able to maintain her cover identity and make a life for herself that she can ethically tolerate?

Criminal Psychologist, Su Xiao Pei, who was an leftover woman in her modern life, was informed by the God Of Marriage, Yue Lao, that her destined lover was in a car accident, his soul was sent to another world. Su Xiao Pei was ordered to bring back this strange man who was connected to her by the red string of fate. Otherwise, she will live the rest of her life in loneliness, with no one to support her.
But how does that man look? No idea.
What’s his personality like? No idea.
What does he do for a living? No idea.
Can she not go? Of course not.
Su Xiaopei, who believes in all things logical has run up against a serious wall this time.
The bottom line: This is a story about a modern female psychologist who has traveled back in time and an adorable warrior as they talk about love and solve crimes.

- Description from Novelupdates

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.

When she reborn, she finally understood; men can never be relied on.
That being the case, she can only rely on herself to win, that
splendid brilliance she yearned for, in this lifetime.

To my scheming Stepmother and ruthless sister, I will
destroy all your backings, pull off your wings, and step on your
arrogance! As for Grandmother whom speaks kindly but has a snake-like heart,
and a father who is hypocritical and exploits advantages; I will tear
off your pretense and cut off your hope! Let’s see how you can still
scheme against me!

Witness her splendid fight against her stepmother, punish scum men,
and create havoc in the imperial court, as she soars with the wind and
rises above the water!

But as for that man who still stands! How dare he play with my heart?

- Description from Novelupdates