The Academy's Barbarian - Chapter 52: Why Did You Come Out There (1)

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.

The Earth mutated and an entire city disappeared from its original world! Su Yi arrived in the Different World strangely with the whole city, where demons ran amok, dynasty hegemony. There was no peace of modern civilization, only the law of jungle! Fortunately, his phone also changed... Gods, demons, monsters, Buddhas, fairies, etc., were all pulled into his mobile phone for his use! I am the king of demons, and I am the Lord of gods!

After spending half a year in the province, Cheng Yang took a luxurious cruise for seven days.
Accidentally hooked up with a CEO on the way.

Later, Cheng Yang found out that he was pregnant.
Just as Cheng Yang was preparing to secretly give birth to the baby, it was a coincidence that he fell asleep in the big president’s bed.

It’s impossible to run with the ball, his man is handsome and rich.
Must cling tightly and can’t be torn down.

- Description from Novelupdates

After dying as a college student, Kain wakes up in a magical world where people form bonds with spiritual creatures to fight alongside them. Determined to rise to the top, he relies on a System and loyal companions.Everything seems to align with his ambitions—except the spiritual creatures he can contract seem to be remarkably…strange