I Become a Martial Arts God in the Chaotic Demon World - Chapter 85: The Power of the Southern Mountain Demon Cleansing Department (Thank you, Yao Xiansheng, for becoming the Alliance Hierarch of this book)

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.

What?! The sticking to her daily, eating her tofu (taking advantage of her ) is a cross-dresser?

Not to mention that he is the Evil Highness!! She had slept beside him, and was touched by him, what a big loss!

Ah–!

Softly on his chest, listening to his pounding, strong heartbeat, her face turned red. Her greatest desire was to be in his arms.

She never dared to dream before, dared not wish for, and thought that in this life there was no such chance. This had been in her most secret heart of hearts, she longed for his warmth, longed for his love.

Even though he had hurt her before, he had given her more tenderness than others.

Being teased, loved, laughed at… had infiltrated into her bloodstream. Love, she did not know when it had taken root, for when she discovered it, it had grown into a towering tree, no longer able to be split open or cut off.

His hug, his warmth, she would not allow him to give it to others. If they were not only for her, she would rather not have them.

- Description from Novelupdates

Loose cultivator Shi Lang gradually found himself in the realm of invincibility. However, when he finally tried to ascend to the higher realm, the spirit of the world was nearly exhausted.

So, between his ascension to a new world or the well-being of his home, he chose the latter and sacrificed his life to save the world.

Nobody knew what he gave up for the world, and he told no one.

Although his sacrifice had gone unsung, there was still someone who witnessed everything. A treasured artifact he carried on his body preserved his soul and let it escape a tragic end.

Eons passed.

The human race stepped out from the age of cultivation into an age of stellar conquest.

The spirit energy in the world was now scarce, but humans found other means to excel.

In this highly-advanced time, Shi Lang's soul has found a chance to be reborn.

What happens when an ancient cultivator that neared the level of a deity before his first death gets a second chance at life in the space age?

Travel to the wizarding world.

“But… what about the wizard who promised to pursue the truth?”

“Why are they all greedy people who pursue power!”

With infinite knowledge comes…

It’s endlessly weird!

- Description from novelbuddy