The Great Demon System - Chapter 33: A Change of Plans

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.

She gnashed her teeth as she faced the abuse from the Imperial concubines in the Imperial harem, forced to endure many calamities.

After travelling through time, Su Yan thought that that ** little bi*ch was right: good people don’t live long and misfortune lasts for a thousand years.

But no matter whichever era she was in, she would tightly grasp the thickest golden thigh and never let go. Looking at it now, it seems that her husband had the thickest thigh.

Till now only modern people were transmigrating back but what happens when an Imperial Concubine transmigrates into modern time? What happens when modern and ancient values clash? Hilarity, action and seduction ensues.

- Description from Novelupdates

What if Magic has always existed ever since the beginning of the Earth we are living on, but history has been written in order to hide these facts. What if the prosperous and well-known people in history is actually a mage?

Enter a magic academy, rule your country. Be at the pinnacle of life! Join me in the journey of Emery and the others in the world of Knights and Magic as he becomes the Earth's Greatest Magus.

One day, Su Qi suddenly discovers he has a peculiar ability: he can see Easter eggs hidden in the world around him.These aren’t just bits of extra information; by performing specific actions, he can unlock hidden rewards.While everyone else is fleeing in terror from a vengeful female ghost, Su Qi is already setting the table for a candlelit dinner, chatting amiably with her.[You acquire her husband's hat, a mysterious artifact that, when thrown, locks onto enemies and delivers a devastating mental shock.]When zombies overrun the streets, and survivors scramble for axes and kitchen knives, Su Qi confidently strides in, wielding a sound system in one hand and a heavy-duty machine gun in the other, casually clearing out the neighborhood.[No one can defeat me in my BGM.]This is the Abyss—the birthplace of despair and decay, where worlds crumble under fear and madness.This is also a paradise where countless seekers pursue the footsteps of gods.Myths of the past and epics of the future are written here in grand and tragic splendor.Until Su Qi shows up.With a mop soaked in the blood of a recently stunned god, Su Qi scrawls a few bold words onto the epic tale:“The Abyssal Garden: No Room for the Idle.”