My military branches can Evolve Infinitely - Chapter 1345 - 688 Divine Sovereign Covers the Earth

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.

Meet Gu Yu—a college dropout and a talented incense maker, and at the same time, the rather stoic protagonist of this story. Despite his somewhat introverted manner, he has a tendency to make sarcastic remarks in his thoughts. One day, after saving a squirrel, a windfall (metaphorically and literally) dropped into his lap. Stumbling into the cultivation world with little help, he was not turned into Superman overnight (as he would like). Apparently, becoming a cultivator would not make your life easier, at least in the beginning.

Somewhere along the road, he ran into Jiang Xiaozhai, a young woman who’s got the brains, the beauty, and maybe one or two secrets of her own. As it turned out, the two made a perfect team—Mulder-and-Scully style. Motivated by many unanswered questions, they had been running up and down the country, getting into all kinds of trouble, and learning more of the modern cultivation world, which is by no means the same as in the ages long past…

- Description from Novelupdates

The youngest Wiseman of the continent, Chu Tian, has traveled 30,000 years back in time to the age of antiquity due to an accident.

This is a prosperous era. Rare herbs, minerals, treasure relics and monsters can be easily found throughout the land.

However, this is also an undeveloped era. Communications, traffic, martial arts and technology are in its early stage of development. Prosperous cities lack lighting while its citizens are uneducated.

Our decisive MC using his future knowledge creates Magic powered light bulbs, magic powered telephones, magic powered cannons, magic powered computers, artificial intelligence, psyche internet. 30,000 years worth of knowledge allows him to create miracles and shine brightly in this era. Allowing him to conquer the land and sit firmly on the throne of the 10 realms.

- Description from Novelupdates

Everything was going so well. It was the perfect path toward greatness.