I Will Live As An Actor - Chapter 112:

Quinn Winter is a young man from another world. One day, he is suddenly chosen to become the new Demon King. But the Demon Kingdom is in big trouble – it's losing a terrible war against the human kingdom called Gran'le.To help his people, Quinn comes up with a risky plan. He will sneak into Gran'le and learn their secrets. But things don’t go as planned. A powerful noble sponsors him, and he ends up joining Heavenward Academy, the top school for training future heroes.At the Academy, there's a big challenge called the Selection. The best students become Paladins – magic knights who fight demons. Quinn doesn’t want to become a Paladin. He is a demon king! But now, he’s stuck in the Selection… and if he wins, he’ll become the very thing he’s supposed to destroy.He started the day badly. Now, things are getting even worse.

The eldest daughter of the Yan family, Yan Jinyu, who has been missing for 16 years, has been found. She is brought back from an orphanage by her fiancé, the Second Master of the Yin family.

An unknown disciple from a small sect battling against the strongest in the cultivation world! The long journey working at cultivation, the realization of destiny and the chance to reach the apex of the world.

Some are born great, some achieve greatness and some have greatness thrust upon them. Zuo Mo is a zombie faced low level cultivator in a minor sect of a little world. Ever since he was picked up by the sect leader two years ago, he has no memories of his earlier life except a recurring nightmare. Navigating the rigid class structure and intricacies of the cultivation world, as one of the lowest possible of the lowest class, Zuo Mo’s dream is to earn money, and lots of it, through being a spiritual plant farmer.

A chance occurrence reveals that someone powerful had changed Zuo’s features and erased his mind. The money grubbing zombie decides to set out on a journey of cultivation to find out answers. Fate colludes with chance, the drums of war are beating, the ghost of his past is coming… …

- 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.