MTL - The Demon King Always Thinks I’m Secretly In Love With Him - Chapter 77

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.

“You mean that Prince Yu wants to marry me?”

“Exactly, young master, Prince Yu wants to marry you!”

“Hell no! Is he out of his mind? Even if woman is a rare species nowadays, as the prince, he could have a chance to marry one. Is it because he got excluded, or maybe he has sexual impotence, so he could only marry a man?”

“No, Prince Yu is charming, majestic, endowed with civil and martial virtues, and also in perfect health.”

“Then why would he marry me?”

“Maybe because of your reputation out there.”

“Reputation? Am I quite famous?”

“Of course. Young master, you’re far-famed.”

“Really? What did they say about me?”

“They said you are ugly, good-for-nothing, short-lived, a freak, with no morals, and shameless…”

…

- Description from Novelupdates

The crumbling Vienna System is unable to stop the rise of the Second Empire, as the Emperor's nephew is about to visit his faithful Paris.Protector of the Apennine, Honorary Chairman of the Rhine Federation, Close Ally of the Kingdom of Spain, French Empire Augustus Jerome Bonaparte:I will make France great again!--------------------(Reasonable historical deduction party, Paradox Interactive game players rejoice!)

Ashlock awoke in the courtyard of a demonic sect… as a tree.

A tree that eats people.

And one that grows stronger over time due to a daily sign-in system and cultivation.