Primordial: I, Dijun, Only Want to Build the Great Desolation - Chapter 299 - 232: The Influence of Sainthood_2

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.

In the year Stardate 1, mankind entered the interstellar age, with interstellar migration, spaceships, alien races, and outer gods...arriving one after another.By the year Stardate 717, Fang Xing looked out upon the cosmic backdrop teeming with dense armies of foreign races and declared that all aliens, cultivators, tentacles, esoteric teachings, and evil gods would be intimidated by his supreme talent and smashed to pieces with his iron fist...Well, this is actually the story of a transmigrator, who whimsically dominates many different worlds with the help of his professional panel...

From the age of 7, Qiao Qiao realised that her family wasn’t quite the same as her friends’ families.

Her father, dressed in all white, said, “Our girl should learn to cultivate immortality with me!”

Her mother, dressed in battle armor, said, “Our girl should train her body to protect herself!”

When discussing it, they decided to solve it with a duel outside.

Her brother secretly asked, “Qiao Qiao, do you want to be in the entertainment industry with me?”

Then, her brother was kicked out of the house by her parents. She prayed that he was okay out there. 

Qiao Qiao sighed. She was really worried about this family.

She silently collected mech building materials. There was no other way, if she learned how to use mechs, she would be able to get a good job. Unfortunately, her unreliable parents didn’t understand.

It seems like the burden of supporting this family was handed over to her.

- Description from Novelupdates

“From today onwards, you will become the Envoy of one of the Main Gods in the Dimensions of Gods. You will travel from one world to another and through that, you will attain what others will never obtain in their entire life.”