The Mage of Eternity - Chapter 623 - : The Newborn Dong Xi!

As long as the land is square, Yan Bicheng should divide the world into four parts.
The dark organization “Ruyimen” has abducted children for many years, trained them as assassin agents, and sent them to the families of various countries for use in order to collect a lot of secrets, and gradually extended their evil hands to the court.
Feng Xiaoya, the favored minister of the King of Yan, suffers from bone melting disease. She is unparalleled in her “sickness and beauty”. For some reason, she abandons the eleventh wife, Qiu Jiang, and puts her under house arrest in the mountains. Qiu Jiang, who has forgotten his past, fled alone on a stormy night. After several twists and turns, on the way back, he met Yi Fei, the third prince of Cheng who was in trouble in a foreign land.
One wants to regain memory, the other wants to regain the throne. The two people who are incompatible with each other walk side by side towards Cheng in a bloody storm… but they find that the Ruyi Gate, which has been entrenched in Chengjing for a hundred years like a poisonous snake, seems to have undergone an unknown shock… …
The situation of the Four Kingdoms is back, and there is only one goal – to eradicate the evil organization Ruyimen!
However, as Qiu Jiang’s memory slowly recovered, a unparalleled secret finally surfaced…
Mrs. Ruyi, who is it? There is another mystery behind Ji Ying’s death?
What is the purpose of this return journey after a narrow escape, and where does it go?

- Description from novelbuddy

Fifty years ago, Dragon City transmigrated to the Other World. Alone in the world, they lifted the banner of Earth’s civilization and fought against the terrifying forces of the Other World.

A man who races against time in the Marvel universe, hungry for pleasure. In the dark night, Nuohe stood on top of the building in a black robe, overlooking the bustling New York City. He lowered the brim of his hat and said in a low voice: They are restless, because I…

He grasped the supreme mystery, transformed into one identity after another, staged a big show, but in the end all became real

Behind him, there are many people standing, Madara with Sharingan open, Artoria holding the holy sword, Doflamingo laughing, proud Gilgamesh…

- Description from novelbuddy

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.