Ultragene Warlord - Chapter 14: Blood Feud

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.

Starting over once more, he has entered this “living game” again in order to control his own fate.

This time, he will not be controlled by others.

Previously the Level 200 Sword King, he will rise to a higher peak in this life.

Methods to earn money! Dungeon conquering strategies! Legendary Quests! Equipment drop locations! Undiscovered battle techniques!

Even the secrets Beta Testers were unknowledgeable of, he knows of them all.

Massive wars, life advancement, entering Godhood, sword reaching to the peak; a legend of a man becoming a Sword God has begun.

Cheng Mingyi was a little lonely throughout his life.

He only brought trouble for the brother who he grew up with and who always had his back. Through fate, due to an accident he became a second generation rich heir, Tan Feiyang. He thought, this time he could repay his Fifth brother.

Jian Ningzhe, became a first class actor with third rated reputation. One day, the infamous Tan Feiyang gave him an olive branch…

Jian Ningzhe refused to accept the hidden meaning behind it. Tan Feiyang “…Did he just ignore my present for him?”

- Description from Novelupdates