Nidome no Yuusha - Chapter 189 – Screams of Exceedingly Deep Forest and Ground [Continuation]

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.

How could a poor graduate student without any background or connections become successful? With a coaching system? An upgrade? This is not a computer game, but real life we’re talking about!

Scorned by the world he was born in, Arthur had no other choice but to learn how to deal with it. Yet, just as his hard work and dedication were about to pay off, the hate towards his origins brought him to his death.

But that wasn't his fate. His future wasn't supposed to end with his head cracking against the edge of the stairs. His bloodline could not die as that would be against the wish of the universe itself.

Thrown to another world, he found himself in a situation where the skills and craft he honed would be no longer of use. His patience, his creativity, his logical thinking were no longer in demand in a world where strength reigned supreme.

Or was it?

My system is overpowered. I'm not shameless enough to deny it.

Scores of women and slaves all around? Those are the wishes of a naive kid, not mine.

Lower the price of those apples by a quarter and we will have a deal!

Dear, stop, I cannot hold any longer!

Jump in and follow Arthur's adventures as he proves that even the illogical world of sword and cultivation has its own rules. Laws, that one can learn, laws, that Arthur sets off to use to his own advantage!

Here is a story about an ordinary hard worker struggling hard in the troubled times of the Three Kingdoms and working hard to farm.

- Description from novelbuddy