The Daily Task of Preventing My Disciple from Turning to the Dark Side - Chapter 24: Gu Yunjue: Take the Chance and KISS Master When He Stared Blankly!

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.

Before rebirth, she was weak and it led to her losing 20 years of experiencing true love because of misunderstandings.

After rebirth, Su Nuo boldly declared her sovereignty: “Gu Chenglan is mine.”

Young Master Gu immediately raised his hand: “Yes yes, my wife is saying the truth.”

Young Master Gu swore an oath: I am a very principled man! Pampering my wife is my only principle. It’s that kind where there’s no bottom line.

Su Nuo’s famous remark: Unexpectedly, I’m suitable to be the richest man’s financial adviser and not only a good doctor. Even if you give me all you got, my family has me!

- Description from Novelupdates

The mentally disabled 13 year old daughter of the Ye family, one day re-births! She rules over the Omnipotent God’s Cauldron, she possesses a spirit cultivation space. She’s no longer the good-for-nothing, abandoned girl who everyone bullies whenever they see her! With her incomparable poisons, even miracle doctors have to move to the side.

Spirit beasts beg for contracts, but too bad, even the God of Beasts have to call her Boss. Scum father, you dare to abandon your wife and daughter, she will surely make him destitute and homeless. People of the world, you dare to bully her, to insult her, she will definitely pay them back a hundredfold.

Reborn again into the world, she returns as a sovereign, but who knew she would attract the nefarious-blood-thirsty-demon him. He’s definitely the sly emperor who doesn’t hesitate to kill and cut down anyone, but he transforms into a harmless foolishly cute prisoner prince of an enemy country……

In the age of the Warring States, the world is at war!

At this moment, a great empire is about to be established, and at this moment, this empire is at stake.

In this vast world, Young Master Qin shouted loudly, “I want this great Qin Wanshi–!”

- Description from novelbuddy