Please Be Patient, Grand Duke - Chapter 82.2

Dressed as [fantasy world] [patriarch], portray the fantasy world as realistic as possible from the perspective of the family, grow spiritual fields, raise spiritual fish, develop various family industries in an all-round way, support salted fish elders to become ancestors to serve as umbrellas, and inspire juniors to bravely venture The Holy Land Academy has come to the fore.

It is not a fantasy of passionate combat, but is based on the promotion of various family industries, capital, facilities, domestic servants, family generals, clansmen, guest officials, in-laws and other elements. Trying to see the “old-fashioned” fantasy world from a fresh perspective.

- Description from novelbuddy

This is the story of a crazy lich who possesses an internal game system and brings catastrophe to the entire world.

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.

Pendulum clocks replaced sand glasses; the world’s first pocket watch ticked through its 100th year. Steam power welcomed the advent of machinery; industries took over farmlands. The study of Science brought humankind out of the clutches of superstitions and pushed them to a path of endless possibilities. And one man witnessed it all.

He was a moth among mayflies, fluttering through as generations replaced generations- fuelled by an endless thirst for knowledge. But fate decided to introduce him to a butterfly- someone alike, yet so different.

Follow ‘The Actor’ Xavier Godwin and ‘The Seeress’ Yue Lin as they delve into the world hidden from the common eyes- a world of magic and mysticism- as they evade the sights of countless hidden organisations, and create a secret society of their own.