The Extra Who Shouldn't Exist - Chapter 83 : The Primordial goddess Avatar

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.

[By the Author that brought you “Return of the Frozen Player”!]The Return of the Fallen Tower Master: The Revival Era of the Magic Tower

The Interstellar Fleet from the game appeared before the ordinary youth, Bai Zhongqi, and the player became the Chancellor of the Empire, opening a new chapter for his brethren and Earth as they set out for the vast sea of stars. The nations of Earth were engaged in cunning and fierce competition for the future of the Intergalactic Era. Bizarre and varied alien civilizations were waiting for Earth’s explorers to discover them. It was a cruel, dark jungle where only the fittest survived, and a world filled with opportunities and magnificent adventures. But for Bai Zhongqi, this was simply a laid-back story about leading Earth’s friends, furiously climbing the tech tree, beating up aliens, and dominating the Galaxy.

Ye Qing transmigrated into a novel. She was only an unimportant character in the novel, and she was free to live a wonderful life by herself.

But, her happiness was short-lived. One day, an adorable girl that looked around three-year-old popped up and called out in a milky voice, “Mom.”

Ye Qing: ???

On another day, a cute and handsome twenty-something guy hugged her. With tears in his eyes, he said in a voice that was full of affection, “Mom!”

Ye Qing: ???

After Ye Qing had somehow inexplicably become the mother of two children, she discovered –

Neither of these children were human!

***

One day, a little girl pulled a certain big boss to the side to whisper, “Dad, mom was patting my head when she was telling me a bedtime story. I felt too comfortable, and I accidently swung my tail out. Mom seems to have seen my tail. What should I do? QAQ.”

- Description from Novelupdates