Immortality begin with Alchemy Grandmaster - Chapter 911 - 373: Old Friends from the Great River, A World of Difference

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.

On the will left behind by the 14 year old suicide victim K:

“Taku Sugawara is the devil. Nobody should believe his words.”

[WSA 2025 ENTRY]“What is this for??”Draven, a Pentagon champion, searches for a real challenge that will test his true strength. However, all his opponents bore him.Then, without warning, he's thrown into a magical world. Here, everything your power, status, and even your worth depends on the color of your Status System I.D.His given goal? Protect the Verdant and lift the curse using his skill, the Veilbreaker.Sounds easy for the likes of him?Think again.Verdants are cursed worse than commoners who have not even the slightest ability!He will bleed every time he lifts a curse!And he has to face beasts, monsters, high-breed animals, higher I.D.s and even gods![You unsealed Naisha skill: Stealth][You obtain Stealth skill.]Challenge accepted!

A lightning strike transmigrated Zu An into another world. In that world, he was known as the tr*sh of Brightmoon City, but for some reason, he was married to the gorgeous and highly talented daughter of the Chu clan?