To achieve immortality, I cultivate using Qi Luck - Chapter 1524 - 591 Sitting Ducks_2

The queen’s essential feature is this: [must be a woman or a feminine-looking man].

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

It tells a poignant love story. He was the most heroic man in history, and before his death he sang a sad song about a woman; she was the most charming woman in history, and before her death she danced a story about steadfast love. The story of the two had no beginning, only an ending of parting in death. After his death, he became a demon for her, and fought fiercely with the immortals of the three realms. After he was killed, his unique seven souls were hidden in various places by the immortals; she became a ghost for him, and before she passed away, she smashed Meng Po's soup bowl, and her soul flew away. Even so, he still vowed to subvert the three realms, find her in the next reincarnation, and marry her, even if it took a thousand years.